Tramadol Hydrochloride

6 ADVERSE REACTIONS The following serious adverse reactions are described, or described in greater detail, in other sections: Addiction, Abuse, and Misuse [see Warnings and Precautions ( 5.1 )] Life-Threatening Respiratory Depression [see Warnings and Precautions ( 5.3 )] Ultra-Rapid Metabolism of Tramadol and Other Risk Factors for Life-threatening Respiratory Depression in Children [see Warnings and Precautions ( 5.6 )] Neonatal Opioid Withdrawal Syndrome [see Warnings and Precautions ( 5.4 )] Interactions with Benzodiazepines or Other CNS Depressants [see Warnings and Precautions ( 5.3 )] Serotonin Syndrome [see Warnings and Precautions ( 5.9 )] Seizures [see Warnings and Precautions ( 5.10 )] Suicide [see Warnings and Precautions ( 5.11 )] Adrenal Insufficiency [see Warnings and Precautions ( 5.13 )] Severe Hypotension [see Warnings and Precautions ( 5.14 )] Gastrointestinal Adverse Reactions [see Warnings and Precautions ( 5.16 )] Hypersensitivity Reactions [see Warnings and Precautions ( 5.17 )] Withdrawal [see Warnings and Precautions ( 5.18 )] Opioid-Induced Hyperalgesia and Allodynia [see Warnings and Precautions ( 5.8 ) The most common incidence of treatment-emergent adverse events (≥15.0%) in patients from clinical trials were dizziness/vertigo, nausea, constipation, headache, somnolence, vomiting and pruritus. To report SUSPECTED ADVERSE REACTIONS, contact Unichem Pharmaceuticals (USA) Inc. at 1-866-562-4616 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch 6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. Tramadol hydrochloride tablets were administered to 550 patients during the double-blind or open-label extension periods in U.S. studies of chronic nonmalignant pain. Of these patients, 375 were 65 years old or older. Table 1 reports the cumulative incidence rate of adverse reactions by 7, 30 and 90 days for the most frequent reactions (5% or more by 7 days). The most frequently reported events were in the central nervous system and gastrointestinal system. Although the reactions listed in the table are felt to be probably related to tramadol hydrochloride tablets administration, the reported rates also include some events that may have been due to underlying disease or concomitant medication. The overall incidence rates of adverse experiences in these trials were similar for tramadol hydrochloride tablets and the active control groups, TYLENOL with Codeine #3 (acetaminophen 300 mg with codeine phosphate 30 mg), and aspirin 325 mg with codeine phosphate 30 mg, however, the rates of withdrawals due to adverse events appeared to be higher in the tramadol hydrochloride tablets groups. Table 1: Cumulative Incidence of Adverse Reactions for tramadol hydrochloride tablets in Chronic Trials of Nonmalignant Pain (N=427) Up to 7 days Up to 30 days Up to 90 days Dizziness/Vertigo 26% 31% 33% Nausea 24% 34% 40% Constipation 24% 38% 46% Headache 18% 26% 32% Somnolence 16% 23% 25% Vomiting 9% 13% 17% Pruritus 8% 10% 11% "CNS Stimulation" 1 7% 11% 14% Asthenia 6% 11% 12% Sweating 6% 7% 9% Dyspepsia 5% 9% 13% Dry Mouth 5% 9% 10% Diarrhea 5% 6% 10% 1 "CNS Stimulation" is a composite of nervousness, anxiety, agitation, tremor, spasticity, euphoria, emotional lability and hallucinations Incidence 1% to Less than 5% Possibly Causally Related The following lists adverse reactions that occurred with an incidence of 1% to less than 5% in clinical trials, and for which the possibility of a causal relationship with tramadol hydrochloride tablets exists. Body as a Whole : Malaise. Cardiovascular : Vasodilation. Central Nervous System : Anxiety, Confusion, Coordination disturbance, Euphoria, Miosis, Nervousness, Sleep disorder. Gastrointestinal : Abdominal pain, Anorexia, Flatulence. Musculoskeletal : Hypertonia. Skin : Rash. Special Senses : Visual disturbance. Urogenital : Menopausal symptoms, Urinary frequency, Urinary retention. Incidence Less than 1%, Possibly Causally Related The following lists adverse reactions that occurred with an incidence of less than 1% in clinical trials of tramadol and/or reported in post-marketing experience with tramadol-containing products. Body as a Whole : Accidental injury, Allergic reaction, Anaphylaxis, Death, Suicidal tendency, Weight loss, Serotonin syndrome (mental status change, hyperreflexia, fever, shivering, tremor, agitation, diaphoresis, seizures and coma). Cardiovascular : Orthostatic hypotension, Syncope, Tachycardia. Central Nervous System : Abnormal gait, Amnesia, Cognitive dysfunction, Depression, Difficulty in concentration, Hallucinations, Paresthesia, Seizure, Tremor. Respiratory : Dyspnea. Skin : Stevens-Johnson syndrome/Toxic epidermal necrolysis, Urticaria, Vesicles. Special Senses : Dysgeusia. Urogenital : Dysuria, Menstrual disorder. Other Adverse Experiences, Causal Relationship Unknown A variety of other adverse events were reported infrequently in patients taking tramadol hydrochloride tablets during clinical trials and/or reported in post-marketing experience. A causal relationship between tramadol hydrochloride tablets and these events has not been determined. However, the most significant events are listed below as alerting information to the physician. Cardiovascular : Abnormal ECG, Hypertension, Hypotension, Myocardial ischemia, Palpitations, Pulmonary edema, Pulmonary embolism. Central Nervous System : Migraine. Gastrointestinal : Gastrointestinal bleeding, Hepatitis, Stomatitis, Liver failure. Laboratory Abnormalities : Creatinine increase, Elevated liver enzymes, Hemoglobin decrease, Proteinuria. Sensory : Cataracts, Deafness, Tinnitus. 6.2 Postmarketing Experience The following adverse reactions have been identified during post-approval use of tramadol hydrochloride tablets. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure. Serotonin syndrome : Cases of serotonin syndrome, a potentially life-threatening condition, have been reported during concomitant use of opioids with serotonergic drugs. Adrenal insufficiency : Cases of adrenal insufficiency have been reported with opioid use, more often following greater than one month of use. Androgen deficiency : Cases of androgen deficiency have occurred with use of opioids for an extended period of time [see Clinical Pharmacology (12.2) ] . Hyperalgesia and Allodynia: Cases of hyperalgesia and allodynia have been reported with opioid therapy of any duration [see Warnings and Precautions ( 5.8 )] QT prolongation/torsade de pointes : Cases of QT prolongation and/or torsade de pointes have been reported with tramadol use. Many of these cases were reported in patients taking another drug labeled for QT prolongation, in patients with a risk factor for QT prolongation (e.g., hypokalemia), or in the overdose setting. Eye disorders – mydriasis Metabolism and nutrition disorders – Hyponatremia: Cases of severe hyponatremia and/or SIADH have been reported in patients taking tramadol, most often in females over the age of 65, and within the first week of therapy [see Warnings and Precautions ( 5.19 )] . Hypoglycemia: Cases of hypoglycemia have been reported in patients taking tramadol. Most reports were in patients with predisposing risk factors, including diabetes or renal insufficiency, or in elderly patients [see Warnings and Precautions ( 5.20 )] . Nervous system disorders – movement disorder, speech disorder Psychiatric disorders – delirium

4 CONTRAINDICATIONS Tramadol hydrochloride tablet is contraindicated for: all children younger than 12 years of age [see Warnings and Precautions (5.4) ]. postoperative management in children younger than 18 years of age following tonsillectomy and/or adenoidectomy [ see Warnings and Precautions (5.4) ]. Tramadol hydrochloride tablet is also contraindicated in patients with: Significant respiratory depression [see Warnings and Precautions (5.3) ]. Acute or severe bronchial asthma in an unmonitored setting or in the absence of resuscitative equipment [see Warnings and Precautions (5.12) ] . Known or suspected gastrointestinal obstruction, including paralytic ileus [see Warnings and Precautions (5.15) ]. Hypersensitivity to tramadol, any other component of this product or opioids [ see Warnings and Precautions (5.16) ]. Concurrent use of monoamine oxidase inhibitors (MAOIs) or use within the last 14 days [see Drug Interactions (7) ]. Children younger than 12 years of age ( 4 ). Postoperative management in children younger than 18 years of age following tonsillectomy and/or adenoidectomy ( 4 ). Significant respiratory depression ( 4 ). Acute or severe bronchial asthma in an unmonitored setting or in the absence of resuscitative equipment ( 4 ). Known or suspected gastrointestinal obstruction, including paralytic ileus ( 4 ). Hypersensitivity to tramadol, any other component of this product or opioids ( 4 ). Concurrent use of monoamine oxidase inhibitors (MAOIs) or use of MAOIs within the last 14 days ( 4 ).

11 DESCRIPTION Tramadol hydrochloride tablets, USP for oral use, are an opioid agonist. The chemical name for tramadol hydrochloride is (±) cis -2-[(dimethylamino)methyl]-1-(3-methoxyphenyl) cyclohexanol hydrochloride. The structural formula is: The molecular weight of tramadol hydrochloride, USP is 299.98. Tramadol hydrochloride is a white or almost white, crystalline powder. It is freely soluble in water and in methanol, very slightly soluble in acetone and has a pKa of 9.41. The n-octanol/water log partition coefficient (logP) is 1.35 at pH 7. Tramadol hydrochloride tablets, USP contain 50 mg of tramadol hydrochloride, USP and are pale yellow in color. Inactive ingredients in the tablet are colloidal silicon dioxide, croscarmellose sodium, hypromellose, iron oxide yellow, lactose monohydrate, magnesium stearate, microcrystalline cellulose, polyethylene glycol, titanium dioxide. Image

2 DOSAGE AND ADMINISTRATION Tramadol hydrochloride tablets should be prescribed only by healthcare professionals who are knowledgeable about the use of opioids and how to mitigate the associated risks. ( 2.1 ) Use the lowest effective dosage for the shortest duration consistent with individual patient treatment goals ( 2.1 ). Reserve titration to higher doses of tramadol hydrochloride tablets for patients in whom lower doses are insufficiently effective and in whom the expected benefits of using a higher dose opioid clearly outweigh the substantial risks. ( 2.1 , 5 ) Initiate the dosing regimen for each patient individually, taking into account the patient's severity of pain, patient response, prior analgesic treatment experience, and risk factors for addiction, abuse, and misuse ( 2.1 ). Many acute pain conditions (e.g., the pain that occurs with a number of surgical procedures or acute musculoskeletal injuries) require no more than a few days of an opioid analgesic. Clinical guidelines on opioid prescribing for some acute pain conditions are available. ( 2.1 ) Initiate the dosing regimen for each patient individually, taking into account the patient's underlying cause and severity of pain, prior analgesic treatment and response, and risk factors for addiction, abuse, and misuse. ( 2.1 , 5.1 ) Respiratory depression can occur at any time during opioid therapy, especially when initiating and following dosage increases with tramadol hydrochloride tablets. Consider this risk when selecting an initial dose and when making dose adjustments. ( 2.1 , 5.2 ) Discuss availability of naloxone with the patient and caregiver and assess each patient's need for access to naloxone, both when initiating and renewing treatment with tramadol hydrochloride tablets. Consider prescribing naloxone based on the patient's risk factors for overdose ( 2.2 , 5.1 , 5.3 , 5.7 ) Start at 25 mg/day and titrate in 25 mg increments as separate doses every 3 days to reach 100 mg/day (25 mg four times a day). Thereafter the total daily dose may be increased by 50 mg as tolerated every 3 days to reach 200 mg/day (50 mg four times a day). After titration, tramadol hydrochloride, tablets 50 mg to 100 mg can be administered as needed for pain relief every 4 to 6 hours not to exceed 400 mg/day ( 2.3 , 2.4 ). Severe Renal Impairment: increase the tramadol hydrochloride tablets, dosing interval to 12 hours, and limit maximum daily dose to 200 mg ( 2.3 ). Severe hepatic impairment: Recommended dose is 50 mg every 12 hours. Do not abruptly discontinue tramadol hydrochloride tablets, in a physically-dependent patient because rapid discontinuation of opioid analgesics has resulted in serious withdrawal symptoms, uncontrolled pain, and suicide ( 2.3 ). 2.1 Important Dosage and Administration Instructions Do not use tramadol hydrochloride tablets concomitantly with other tramadol-containing products. Do not administer tramadol hydrochloride tablets at a dose exceeding 400 mg per day. Tramadol hydrochloride tablets should be prescribed only by healthcare professionals who are knowledgeable about the use of opioids and how to mitigate the associated risks. Use the lowest effective dosage for the shortest duration of time consistent with individual patient treatment goals [see Warnings and Precautions ( 5 )] . Because the risk of overdose increases as opioid doses increase, reserve titration to higher doses of tramadol hydrochloride tablets for patients in whom lower doses are insufficiently effective and in whom the expected benefits of using a higher dose opioid clearly outweigh the substantial risks. Many acute pain conditions (e.g., the pain that occurs with a number of surgical procedures or acute musculoskeletal injuries) require no more than a few days of an opioid analgesic. Clinical guidelines on opioid prescribing for some acute pain conditions are available. There is variability in the opioid analgesic dose and duration needed to adequately manage pain due both to the cause of pain and to individual patient factors. Initiate the dosing regimen for each patient individually, taking into account the patient's underlying cause and severity of pain, prior analgesic treatment and response, and risk factors for addiction, abuse, and misuse [see Warnings and Precautions ( 5.1 )] . Respiratory depression can occur at any time during opioid therapy, especially when initiating and following dosage increases with tramadol hydrochloride tablets. Consider this risk when selecting an initial dose and when making dose adjustments [see Warnings and Precautions ( 5 )] . 2.2 Patient Access to Naloxone for the Emergency Treatment of Opioid Overdose Discuss the availability of naloxone for the emergency treatment of opioid overdose with the patient and caregiver and assess the potential need for access to naloxone, both when initiating and renewing treatment with tramadol hydrochloride tablets [see Warnings and Precautions ( 5.3 ), Patient Counseling Information ( 17 )] . Inform patients and caregivers about the various ways to obtain naloxone as permitted by individual state naloxone dispensing and prescribing requirements or guidelines (e.g., by prescription, directly from a pharmacist, or as part of a community-based program). Consider prescribing naloxone, based on the patient's risk factors for overdose, such as concomitant use of CNS depressants, a history of opioid use disorder, or prior opioid overdose. However, the presence of risk factors for overdose should not prevent the proper management of pain in any given patient [see Warnings and Precautions ( 5.1 , 5.3 , 5.7 )] . Consider prescribing naloxone if the patient has household members (including children) or other close contacts at risk for accidental exposure or overdose. 2.3 Initial Dosage Initiating Treatment with tramadol hydrochloride tablets Initiate treatment at the lowest dose necessary to achieve adequate analgesia. Titrate the dose based upon the individual patient's response to their initial dose of tramadol hydrochloride tablets. For patients not requiring rapid onset of analgesic effect, the tolerability of tramadol hydrochloride tablets can be improved by initiating therapy with the following titration regimen: Start tramadol hydrochloride tablets at 25 mg/day and titrate in 25 mg increments as separate doses every 3 days to reach 100 mg/day (25 mg four times a day). Thereafter the total daily dose may be increased by 50 mg as tolerated every 3 days to reach 200 mg/day (50 mg four times a day). After titration, tramadol hydrochloride tablets 50 to 100 mg can be administered as needed for pain relief every 4 to 6 hours not to exceed 400 mg/day. For the subset of patients for whom rapid onset of analgesic effect is required and for whom the benefits outweigh the risk of discontinuation due to adverse events associated with higher initial doses, tramadol hydrochloride tablets 50 mg to 100 mg can be administered as needed for pain relief every four to six hours, not to exceed 400 mg per day. Conversion from Tramadol to Extended-Release Tramadol The relative bioavailability of tramadol compared to extended-release tramadol is unknown, so conversion to extended-release formulations may lead to increased risk of excessive sedation and respiratory depression. Dosage Modification in Patients with Hepatic Impairment The recommended dose for adult patients with severe hepatic impairment is 50 mg every 12 hours. Dosage Modification in Patients with Renal Impairment In all patients with creatinine clearance less than 30 mL/min, it is recommended that the dosing interval of tramadol hydrochloride tablets be increased to 12 hours, with a maximum daily dose of 200 mg. Since only 7% of an administered dose is removed by hemodialysis, dialysis patients can receive their regular dose on the day of dialysis. Dosage Modification in Geriatric Patients Do not exceed a total dose of 300 mg/day in patients over 75 years old. 2.4 Titration and Maintenance of Therapy Individually titrate tramadol hydrochloride tablets to a dose that provides adequate analgesia and minimizes adverse reactions. Continually reevaluate patients receiving tramadol hydrochloride tablets to assess the maintenance of pain control, signs and symptoms of opioid withdrawal, and other adverse reactions, as well as to reassess for the development of addiction, abuse, or misuse [see Warnings and Precautions (5.1) and Withdrawal (5.18) ] . Frequent communication is important among the prescriber, other members of the healthcare team, the patient, and the caregiver/family during periods of changing analgesic requirements, including initial titration. If the level of pain increases after dosage stabilization, attempt to identify the source of increased pain before increasing the tramadol hydrochloride tablets dosage. If after increasing the dosage, unacceptable opioid-related adverse reactions are observed (including an increase in pain after dosage increase), consider reducing the dosage [see Warnings and Precautions (5) ] . Adjust the dosage to obtain an appropriate balance between management of pain and opioid-related adverse reactions. 2.5 Safe Reduction or Discontinuation of tramadol hydrochloride tablets Do not abruptly discontinue tramadol hydrochloride tablets in patients who may be physically dependent on opioids. Rapid discontinuation of opioid analgesics in patients who are physically dependent on opioids has resulted in serious withdrawal symptoms, uncontrolled pain, and suicide. Rapid discontinuation has also been associated with attempts to find other sources of opioid analgesics, which may be confused with drug-seeking for abuse. Patients may also attempt to treat their pain or withdrawal symptoms with illicit opioids, such as heroin, and other substances. When a decision has been made to decrease the dose or discontinue therapy in an opioid-dependent patient taking tramadol hydrochloride tablets, there are a variety of factors that should be considered, including the total daily dose of opioid (including tramadol hydrochloride tablets) the patient has been taking, the duration of treatment, the type of pain being treated, and the physical and psychological attributes of the patient. It is important to ensure ongoing care of the patient and to agree on an appropriate tapering schedule and follow-up plan so that patient and provider goals and expectations are clear and realistic. When opioid analgesics are being discontinued due to a suspected substance use disorder, evaluate and treat the patient, or refer for evaluation and treatment of the substance use disorder. Treatment should include evidence-based approaches, such as medication assisted treatment of opioid use disorder. Complex patients with comorbid pain and substance use disorders may benefit from referral to a specialist. There are no standard opioid tapering schedules that are suitable for all patients. Good clinical practice dictates a patient-specific plan to taper the dose of the opioid gradually. For patients on tramadol hydrochloride tablets who are physically opioid-dependent, initiate the taper by a small enough increment, (e.g., no greater than 10% to 25% of the total daily dose) to avoid withdrawal symptoms, and proceed with dose-lowering at an interval of every 2 to 4 weeks. Patients who have been taking opioids for briefer periods of time may tolerate a more rapid taper. It may be necessary to provide the patient with a lower dosage strength to accomplish a successful taper. Reassess the patient frequently to manage pain and withdrawal symptoms, should they emerge. Common withdrawal symptoms include restlessness, lacrimation, rhinorrhea, yawning, perspiration, chills, myalgia, and mydriasis. Other signs and symptoms also may develop, including irritability, anxiety, backache, joint pain, weakness, abdominal cramps, insomnia, nausea, anorexia, vomiting, diarrhea, or increased blood pressure, respiratory rate, or heart rate. If withdrawal symptoms arise, it may be necessary to pause the taper for a period of time or raise the dose of the opioid analgesic to the previous dose, and then proceed with a slower taper. In addition, evaluate patients for any changes in mood, emergence of suicidal thoughts, or use of other substances. When managing patients taking opioid analgesics, particularly those who have been treated for an extended period of time, and/or with high doses for chronic pain, ensure that a multimodal approach to pain management, including mental health support (if needed), is in place prior to initiating an opioid analgesic taper. A multimodal approach to pain management may optimize the treatment of chronic pain, as well as assist with the successful tapering of the opioid analgesic [see Warnings and Precautions (5. 17 ), Drug Abuse and Dependence ( 9.3 )] .

1 INDICATIONS AND USAGE Tramadol hydrochloride tablets are indicated in adults for the management of pain severe enough to require an opioid analgesic and for which alternative treatments are inadequate. Limitations of Use Because of the risks of addiction, abuse, and misuse with opioids, which can occur at any dosage or duration [see Warnings and Precautions ( 5.1 )] , reserve tramadol hydrochloride tablets for use in patients for whom alternative treatment options [e.g., non-opioid analgesics or opioid combination products]: Have not been tolerated or are not expected to be tolerated. Have not provided adequate analgesia or are not expected to provide adequate analgesia. Tramadol hydrochloride tablets should not be used for an extended period of time unless the pain remains severe enough to require an opioid analgesic and for which alternative treatment options continue to be inadequate. Tramadol hydrochloride tablets are opioid agonist indicated in adults for the management of pain severe enough to require an opioid analgesic and for which alternative treatments are inadequate ( 1 ). Limitations of Use ( 1 ) Because of the risks of addiction, abuse, and misuse with opioids, which can occur at any dosage or duration, reserve tramadol hydrochloride tablets for use in patients for whom alternative treatment options [e.g., non-opioid analgesics or opioid combination products]: Have not been tolerated or are not expected to be tolerated ( 1 ) Have not provided adequate analgesia, or are not expected to provide adequate analgesia ( 1 ) Tramadol hydrochloride tablets should not be used for an extended period of times unless the pain remains severe enough to require an opioid analgesic and for which alternative treatment options continue to be inadequate.

9 DRUG ABUSE AND DEPENDENCE 9.1 Controlled Substance Tramadol hydrochloride tablets contain tramadol, a Schedule IV controlled substance. 9.2 Abuse Tramadol hydrochloride tablets contain tramadol, a substance with potential for misuse and abuse, which can lead to the development of substance use disorder, including addiction [see Warnings and Precautions ( 5.1 )] . Misuse is the intentional use, for therapeutic purposes, of a drug by an individual in a way other than prescribed by a healthcare provider or for whom it was not prescribed. Abuse is the intentional, non-therapeutic use of a drug, even once, for its desirable psychological or physiological effects. Drug addiction is a cluster of behavioral, cognitive, and physiological phenomena that may include a strong desire to take the drug, difficulties in controlling drug use (e.g., continuing drug use despite harmful consequences, giving a higher priority to drug use than other activities and obligations), and possible tolerance or physical dependence. Misuse and abuse of tramadol hydrochloride tablets increases risk of overdose, which may lead to central nervous system and respiratory depression, hypotension, seizures, and death. The risk is increased with concurrent abuse of tramadol hydrochloride tablets with alcohol and other CNS depressants. Abuse of and addiction to opioids in some individuals may not be accompanied by concurrent tolerance and symptoms of physical dependence. In addition, abuse of opioids can occur in the absence of addiction. All patients treated with opioids require careful and frequent reevaluation for signs of misuse, abuse, and addiction, because use of opioid analgesic products carries the risk of addiction even under appropriate medical use. Patients at high risk of tramadol hydrochloride tablets abuse include those with a history of prolonged use of any opioid, including products containing tramadol, those with a history of drug or alcohol abuse, or those who use tramadol hydrochloride tablets in combination with other abused drugs. "Drug-seeking" behavior is very common in persons with substance use disorders. Drug-seeking tactics include emergency calls or visits near the end of office hours, refusal to undergo appropriate examination, testing, or referral, repeated "loss" of prescriptions, tampering with prescriptions, and reluctance to provide prior medical records or contact information for other treating healthcare provider(s). "Doctor shopping" (visiting multiple prescribers to obtain additional prescriptions) is common among people who abuse drugs and people with substance use disorder. Preoccupation with achieving adequate pain relief can be appropriate behavior in a patient with inadequate pain control. Tramadol hydrochloride tablets, like other opioids, can be diverted for nonmedical use into illicit channels of distribution. Careful record-keeping of prescribing information, including quantity, frequency, and renewal requests, as required by state and federal law, is strongly advised. Proper assessment of the patient, proper prescribing practices, periodic reevaluation of therapy, and proper dispensing and storage are appropriate measures that help to limit abuse of opioid drugs. Risks Specific to Abuse of tramadol hydrochloride tablets Abuse of tramadol hydrochloride tablets poses a risk of overdose and death. The risk is increased with concurrent use of tramadol hydrochloride tablets with alcohol and/or other CNS depressants. Tramadol hydrochloride tablets are approved for oral use only. Parenteral drug abuse is commonly associated with transmission of infectious diseases such as hepatitis and HIV. 9.3 Dependence Both tolerance and physical dependence can develop during use of opioid therapy. Tolerance is a physiological state characterized by a reduced response to a drug after repeated administration (i.e., a higher dose of a drug is required to produce the same effect that was once obtained at a lower dose). Physical dependence is a state that develops as a result of a physiological adaptation in response to repeated drug use, manifested by withdrawal signs and symptoms after abrupt discontinuation or a significant dose reduction of a drug. Withdrawal may be precipitated through the administration of drugs with opioid antagonist activity (e.g., naloxone), mixed agonist/antagonist analgesics (e.g., pentazocine, butorphanol, nalbuphine), or partial agonists (e.g., buprenorphine). Physical dependence may not occur to a clinically significant degree until after several days to weeks of continued use. Do not abruptly discontinue tramadol hydrochloride tablets in a patient physically dependent on opioids. Rapid tapering of tramadol hydrochloride tablets in a patient physically dependent on opioids may lead to serious withdrawal symptoms, uncontrolled pain, and suicide. Rapid discontinuation has also been associated with attempts to find other sources of opioid analgesics, which may be confused with drug-seeking for abuse. When discontinuing tramadol hydrochloride tablets, gradually taper the dosage using a patient-specific plan that considers the following: the dose of tramadol hydrochloride tablets the patient has been taking, the duration of treatment, and the physical and psychological attributes of the patient. To improve the likelihood of a successful taper and minimize withdrawal symptoms, it is important that the opioid tapering schedule is agreed upon by the patient. In patients taking opioids for an extended period of time at high doses, ensure that a multimodal approach to pain management, including mental health support (if needed), is in place prior to initiating an opioid analgesic taper [see Dosage and Administration ( 2.5 ), and Warnings and Precautions ( 5.18 )] . Infants born to mothers physically dependent on opioids will also be physically dependent and may exhibit respiratory difficulties and withdrawal signs [see Use in Specific Populations ( 8.1 )] .

10 OVERDOSAGE Clinical Presentation Acute overdosage with tramadol hydrochloride tablets can be manifested by respiratory depression, somnolence progressing to stupor or coma, skeletal muscle flaccidity, cold and clammy skin, constricted pupils, and, in some cases, pulmonary edema, bradycardia, QT prolongation, hypotension, partial or complete airway obstruction, atypical snoring, seizures, and death. Marked mydriasis rather than miosis may be seen with hypoxia in overdose situations. Deaths due to overdose have been reported with abuse and misuse of tramadol [see Warnings and Precautions (5.1); Drug Abuse and Dependence (9.2)] . Review of case reports has indicated that the risk of fatal overdose is further increased when tramadol is abused concurrently with alcohol or other CNS depressants, including other opioids. Treatment of Overdose In case of overdose, priorities are the re-establishment of a patent and protected airway and institution of assisted or controlled ventilation, if needed. Employ other supportive measures (including oxygen and vasopressors) in the management of circulatory shock and pulmonary edema as indicated. Cardiac arrest or serious arrhythmias will require advanced life-supporting measures. Because strategies for the management of overdose are continually evolving, it is advisable to contact a poison control center (where available) to determine the latest recommendations for the management of an overdose. Opioid antagonists, such as naloxone, are specific antidotes to respiratory depression resulting from opioid overdose. For clinically significant respiratory or circulatory depression secondary to opioid overdose, administer an opioid antagonist. While naloxone will reverse some, but not all, symptoms caused by overdosage with tramadol, the risk of seizures is also increased with naloxone administration. In animals, convulsions following the administration of toxic doses of tramadol hydrochloride tablets could be suppressed with barbiturates or benzodiazepines but were increased with naloxone. Naloxone administration did not change the lethality of an overdose in mice. Hemodialysis is not expected to be helpful in an overdose because it removes less than 7% of the administered dose in a 4-hour dialysis period. Because the duration of opioid reversal is expected to be less than the duration of action of tramadol in tramadol hydrochloride tablets, carefully monitor the patient until spontaneous respiration is reliably re established. If the response to an opioid antagonist is suboptimal or only brief in nature, administer additional antagonist as directed by the product's prescribing information. In an individual physically dependent on opioids, administration of the recommended usual dosage of the antagonist will precipitate an acute withdrawal syndrome. The severity of the withdrawal symptoms experienced will depend on the degree of physical dependence and the dose of the antagonist administered. If a decision is made to treat serious respiratory depression in the physically dependent patient, administration of the antagonist should be begun with care and by titration with smaller than usual doses of the antagonist.

7 DRUG INTERACTIONS Table 2: Clinically Significant Drug Interactions with tramadol hydrochloride tablets Inhibitors of CYP2D6 Clinical Impact: The concomitant use of tramadol hydrochloride tablets and CYP2D6 inhibitors may result in an increase in the plasma concentration of tramadol and a decrease in the plasma concentration of M1, particularly when an inhibitor is added after a stable dose of tramadol hydrochloride tablets are achieved. Since M1 is a more potent μ-opioid agonist, decreased M1 exposure could result in decreased therapeutic effects, and may result in signs and symptoms of opioid withdrawal in patients who had developed physical dependence to tramadol. Increased tramadol exposure can result in increased or prolonged therapeutic effects and increased risk for serious adverse events including seizures and serotonin syndrome. After stopping a CYP2D6 inhibitor, as the effects of the inhibitor decline, the tramadol plasma concentration will decrease and the M1 plasma concentration will increase. This could increase or prolong therapeutic effects but also increase adverse reactions related to opioid toxicity, such as potentially fatal respiratory depression [see Clinical Pharmacology (12.3 )] . Intervention: If concomitant use of a CYP2D6 inhibitor is necessary, evaluate patients at frequent intervals for adverse reactions including opioid withdrawal, seizures and serotonin syndrome. If a CYP2D6 inhibitor is discontinued, consider lowering tramadol hydrochloride tablets dosage until stable drug effects are achieved. Evaluate patients at frequent intervals for adverse events including respiratory depression and sedation. Examples: Quinidine, fluoxetine, paroxetine and bupropion Inhibitors of CYP3A4 Clinical Impact: The concomitant use of tramadol hydrochloride tablets and CYP3A4 inhibitors can increase the plasma concentration of tramadol and may result in a greater amount of metabolism via CYP2D6 and greater levels of M1. Follow patients closely for increased risk of serious adverse events including seizures and serotonin syndrome, and adverse reactions related to opioid toxicity including potentially fatal respiratory depression, particularly when an inhibitor is added after a stable dose of tramadol hydrochloride tablets are achieved. After stopping a CYP3A4 inhibitor, as the effects of the inhibitor decline, the tramadol plasma concentration will decrease [see Clinical Pharmacology (12.3) ] , resulting in decreased opioid efficacy or a withdrawal syndrome in patients who had developed physical dependence to tramadol. Intervention: If concomitant use is necessary, consider dosage reduction of tramadol hydrochloride tablets until stable drug effects are achieved and evaluate patients at frequent intervals on the signs and symptoms of seizures, serotonin syndrome, and signs of respiratory depression and sedation. If a CYP3A4 inhibitor is discontinued, consider increasing the tramadol hydrochloride tablets dosage until stable drug effects are achieved and monitor patients at frequent intervals for signs and symptoms of opioid withdrawal. Examples : Macrolide antibiotics (e.g., erythromycin), azole-antifungal agents (e.g. ketoconazole), protease inhibitors (e.g., ritonavir) CYP3A4 Inducers Clinical Impact: The concomitant use of tramadol hydrochloride tablets and CYP3A4 inducers can decrease the plasma concentration of tramadol [see Clinical Pharmacology (12.3) ] , resulting in decreased efficacy or onset of a withdrawal syndrome in patients who have developed physical dependence to tramadol. After stopping a CYP3A4 inducer, as the effects of the inducer decline, the tramadol plasma concentration will increase [see Clinical Pharmacology (12.3) ] , which could increase or prolong both the therapeutic effects and adverse reactions, and may cause seizures, serotonin syndrome, and/or potentially fatal respiratory depression. Intervention: If concomitant use is necessary, consider increasing the tramadol hydrochloride tablets dosage until stable drug effects are achieved. Assess patients for signs of opioid withdrawal. If a CYP3A4 inducer is discontinued, consider tramadol hydrochloride tablets dosage reduction and evaluate patients at frequent intervals for signs of respiratory depression and sedation. Patients taking carbamazepine, a CYP3A4 inducer, may have a significantly reduced analgesic effect of tramadol. Because carbamazepine increases tramadol metabolism and because of the seizure risk associated with tramadol, concomitant administration of tramadol hydrochloride tablets and carbamazepine is not recommended. Examples: Rifampin, carbamazepine, phenytoin Benzodiazepines and Other Central Nervous System (CNS) Depressants Clinical Impact: Due to additive pharmacologic effect, the concomitant use of benzodiazepines or other CNS depressants, including alcohol, increases the risk of respiratory depression, profound sedation, coma, and death. Intervention: Reserve concomitant prescribing of these drugs for use in patients for whom alternative treatment options are inadequate. Limit dosages and durations to the minimum required. Inform patients and caregivers of this potential interaction, educate them on the signs and symptoms of respiratory depression (including sedation) [see Warnings and Precautions (5.7) ] . If concomitant use is warranted, consider prescribing naloxone for the emergency treatment of opioid overdose [see Dosage and Administration ( 2.2 ), Warnings and Precautions ( 5.1 , 5.3 , 5.7 )]. Examples: Benzodiazepines and other sedatives/hypnotics, anxiolytics, tranquilizers, muscle relaxants, general anesthetics, antipsychotics, other opioids, and alcohol. Serotonergic Drugs Clinical Impact: The concomitant use of opioids with other drugs that affect the serotonergic neurotransmitter system has resulted in serotonin syndrome. Intervention: If concomitant use is warranted, frequently evaluate the patient, particularly during treatment initiation and dose adjustment. Discontinue tramadol immediately if serotonin syndrome is suspected. Examples: Selective serotonin reuptake inhibitors (SSRIs), serotonin and norepinephrine reuptake inhibitors (SNRIs), tricyclic antidepressants (TCAs), triptans, 5-HT3 receptor antagonists, drugs that affect the serotonin neurotransmitter system (e.g., mirtazapine, trazodone, tramadol), certain muscle relaxants (i.e., cyclobenzaprine, metaxalone), monoamine oxidase (MAO) inhibitors (those intended to treat psychiatric disorders and also others, such as linezolid and intravenous methylene blue). Monoamine Oxidase Inhibitors (MAOIs) Clinical Impact: MAOI interactions with opioids may manifest as serotonin syndrome [see Warnings and Precautions (5.9) ] or opioid toxicity (e.g., respiratory depression, coma) [see Warnings and Precautions (5.3) ] . Intervention: Do not use Tramadol Hydrochloride in patients taking MAOIs or within 14 days of stopping such treatment Examples: phenelzine, tranylcypromine, linezolid Mixed Agonist/Antagonist and Partial Agonist Opioid Analgesics Clinical Impact: May reduce the analgesic effect of tramadol hydrochloride tablets and/or precipitate withdrawal symptoms. Intervention: Avoid concomitant use Examples: butorphanol, nalbuphine, pentazocine, buprenorphine Muscle Relaxants Clinical Impact: Tramadol may enhance the neuromuscular blocking action of skeletal muscle relaxants and produce an increased degree of respiratory depression. Intervention: Because respiratory depression may be greater than otherwise expected, decrease the dosage of tramadol hydrochloride tablets and/or the muscle relaxant as necessary. Due to the risk of respiratory depression with concomitant use of skeletal muscle relaxants and opioids, consider prescribing naloxone for the emergency treatment of opioid overdose [see Dosage and Administration ( 2.2 ), Warnings and Precautions ( 5.3 , 5.7 )]. Diuretics Clinical Impact: Opioids can reduce the efficacy of diuretics by inducing the release of antidiuretic hormone. Intervention: Evaluate patients for signs of diminished diuresis and/or effects on blood pressure and increase the dosage of the diuretic as needed. Anticholinergic Drugs Clinical Impact: The concomitant use of anticholinergic drugs may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. Intervention: Evaluate patients for signs of urinary retention or reduced gastric motility when tramadol hydrochloride tablets are used concomitantly with anticholinergic drugs. Digoxin Clinical Impact: Intervention: Post-marketing surveillance of tramadol has revealed rare reports of digoxin toxicity. Evaluate patients at frequent intervals for signs of digoxin toxicity and adjust dosage of digoxin as needed. Warfarin Clinical Impact: Post-marketing surveillance of tramadol has revealed rare reports of alteration of warfarin effect, including elevation of prothrombin times Intervention: Frequently reevaluate the prothrombin time of patients on warfarin for signs of an interaction and adjust the dosage of warfarin as needed Mixed Agonist/Antagonist and Partial Agonist Opioid Analgesics : Avoid use with tramadol hydrochloride tablets because they may reduce analgesic effect of tramadol hydrochloride or precipitate withdrawal symptoms.

12 CLINICAL PHARMACOLOGY 12.1 Mechanism of Action Tramadol hydrochloride tablets contain tramadol, an opioid agonist and inhibitor of norepinephrine and serotonin re- uptake. Although the mode of action is not completely understood, the analgesic effect of tramadol is believed to be due to both binding to µ-opioid receptors and weak inhibition of re- uptake of norepinephrine and serotonin. Opioid activity is due to both low affinity binding of the parent compound and higher affinity binding of the O -demethylated metabolite M1 to µ-opioid receptors. In animal models, M1 is up to 6 times more potent than tramadol in producing analgesia and 200 times more potent in µ opioid binding. Tramadol-induced analgesia is only partially antagonized by the opioid antagonist naloxone in several animal tests. The relative contribution of both tramadol and M1 to human analgesia is dependent upon the plasma concentrations of each compound [see Clinical Pharmacology (12.2)] . Analgesia in humans begins approximately within one hour after administration and reaches a peak in approximately two to three hours. 12.2 Pharmacodynamics Effects on the Central Nervous System Tramadol produces respiratory depression by direct action on brain stem respiratory centers. The respiratory depression involves a reduction in the responsiveness of the brain stem respiratory centers to both increases in carbon dioxide tension and electrical stimulation. Tramadol administration may produce a constellation of symptoms including nausea and vomiting, dizziness, and somnolence. Tramadol causes miosis, even in total darkness. Pinpoint pupils are a sign of opioid overdose but are not pathognomonic (e.g., pontine lesions of hemorrhagic or ischemic origins may produce similar findings). Marked mydriasis rather than miosis may be seen due to hypoxia in overdose situations. Effects on the Gastrointestinal Tract and Other Smooth Muscle Tramadol causes a reduction in motility associated with an increase in smooth muscle tone in the antrum of the stomach and duodenum. Digestion of food in the small intestine is delayed and propulsive contractions are decreased. Propulsive peristaltic waves in the colon are decreased, while tone may be increased to the point of spasm resulting in constipation. Other opioid- induced effects may include a reduction in biliary and pancreatic secretions, spasm of sphincter of Oddi, and transient elevations in serum amylase. Effects on the Cardiovascular System Tramadol produces peripheral vasodilation, which may result in orthostatic hypotension or syncope. Manifestations of peripheral vasodilation may include pruritus, flushing, red eyes, sweating and/or orthostatic hypotension. The effect of oral tramadol on the QTcF interval was evaluated in a double-blind, randomized, four-way crossover, placebo- and positive- (moxifloxacin) controlled study in 68 adult male and female healthy subjects. At a 600 mg/day dose (1.5-fold the maximum immediate-release daily dose), the study demonstrated no significant effect on the QTcF interval. Effects on the Endocrine System Opioids inhibit the secretion of adrenocorticotropic hormone (ACTH), cortisol, and luteinizing hormone (LH) in humans. They also stimulate prolactin, growth hormone (GH) secretion, and pancreatic secretion of insulin and glucagon [see Warnings and Precautions (5.11 ); Adverse Reactions (6) ] . Use of opioids for an extended period of time may influence the hypothalamic-pituitary-gonadal axis, leading to androgen deficiency that may manifest as low libido, impotence, erectile dysfunction, amenorrhea, or infertility. The causal role of opioids in the clinical syndrome of hypogonadism is unknown because the various medical, physical, lifestyle, and psychological stressors that may influence gonadal hormone levels have not been adequately controlled for in studies conducted to date [see Adverse Reactions (6) ] . Effects on the Immune System Opioids have been shown to have a variety of effects on components of the immune system in in vitro and animal models. The clinical significance of these findings is unknown. Overall, the effects of opioids appear to be modestly immunosuppressive. Concentration–Efficacy Relationships The minimum effective analgesic concentration will vary widely among patients, especially among patients who have been previously treated with extended-release opioid agonists. The minimum effective analgesic concentration of tramadol for any individual patient may increase over time due to an increase in pain, the development of a new pain syndrome and/or the development of analgesic tolerance [see Dosage and Administration (2 )] . Concentration–Adverse Reaction Relationships There is a relationship between increasing tramadol plasma concentration and increasing frequency of dose-related opioid adverse reactions such as nausea, vomiting, CNS effects, and respiratory depression. In opioid-tolerant patients, the situation may be altered by the development of tolerance to opioid-related adverse reactions [see Dosage and Administration (2) ] . 12.3 Pharmacokinetics The analgesic activity of tramadol hydrochloride tablets are due to both parent drug and the M1 metabolite [see Clinical Pharmacology (12.1,12.2)] . Tramadol is administered as a racemate and both the [-] and [+] forms of both tramadol and M1 are detected in the circulation. Linear pharmacokinetics have been observed following multiple doses of 50 and 100 mg to steady-state. Absorption The mean absolute bioavailability of a 100 mg oral dose is approximately 75%. The mean peak plasma concentration of racemic tramadol and M1 occurs at two and three hours, respectively, after administration in healthy adults. In general, both enantiomers of tramadol and M1 follow a parallel time course in the body following single and multiple doses although small differences (~ 10%) exist in the absolute amount of each enantiomer present. Steady-state plasma concentrations of both tramadol and M1 are achieved within two days with four times per day dosing. There is no evidence of self-induction (see Figure 1 and Table 3 below). Table 3: Mean (%CV) Pharmacokinetic Parameters for Racemic Tramadol and M1 Metabolite Population/Dosage Regimen a Parent Drug/ Metabolite Peak Conc.(ng/mL) Time to Peak (hrs) Clearance/F b (mL/min/Kg) t 1/2 (hrs) Healthy Adults, Tramadol 592 (30) 2.3 (61) 5.90 (25) c 6.7 (15) 100 mg aid, MD p.o. M1 110 (29) 2.4 (46) 7.0 (14) Healthy Adults, Tramadol 308 (25) 1.6 (63) 8.50 (31) c 5.6 (20) 100 mg aid, MD p.o. M1 55.0 (36) 3.0 (51) 6.7(16) Geriatric (> 75 yrs) Tramadol 208 (31)d 2.1 (19) d 6.89 (25) c 7.0 (23) d 50 mg SD p.o. M1 Hepatic impaired, Tramadol 217 (11) 1.9 (16) 4.23 (56) c 13.3 (11) 50 mg SD p.o. M1 19.4 (12) 9.8 (20) 18.5 (15) Renal Impaired Tramadol c c 4.23 (54) c 10.6 (31) CLcr 10-30 ml/min M1 c c 11.5 (40) 100 mg SD i.v. Renal Impaired Tramadol c c 3.73 (17) c 11.0 (29) CLcr <5 ml/min M1 c c 16.9 (18) 100 mg SD i.v a SD = Single dose, MD = Multiple dose, p.o.= Oral administration, i.v.= Intravenous administration, q.i.d. = Four times daily b F represents the oral bioavailability of tramadol c Not applicable d Not measured Food Effects Oral administration of tramadol hydrochloride tablets with food does not significantly affect its rate or extent of absorption, therefore, tramadol hydrochloride tablets can be administered without regard to food. Distribution The volume of distribution of tramadol was 2.6 and 2.9 liters/kg in male and female subjects, respectively, following a 100 mg intravenous dose. The binding of tramadol to human plasma proteins is approximately 20% and binding also appears to be independent of concentration up to 10 mcg/mL. Saturation of plasma protein binding occurs only at concentrations outside the clinically relevant range. Elimination Tramadol is eliminated primarily through metabolism by the liver and the metabolites are eliminated primarily by the kidneys. The mean (%CV) apparent total clearance of tramadol after a single 100 mg oral dose is 8.50 (31) mL/min/kg. The mean terminal plasma elimination half- lives of racemic tramadol and racemic M1 are 6.3 ± 1.4 and 7.4 ± 1.4 hours, respectively. The plasma elimination half-life of racemic tramadol increased from approximately six hours to seven hours upon multiple dosing. Metabolism Tramadol is extensively metabolized after oral administration by a number of pathways, including CYP2D6 and CYP3A4, as well as by conjugation of parent and metabolites. Approximately 30% of the dose is excreted in the urine as unchanged drug, whereas 60% of the dose is excreted as metabolites. The remainder is excreted either as unidentified or as unextractable metabolites. The major metabolic pathways appear to be N - and O- demethylation and glucuronidation or sulfation in the liver. One metabolite ( O -desmethyltramadol, denoted M1) is pharmacologically active in animal models. Formation of M1 is dependent on CYP2D6 and as such is subject to inhibition, which may affect the therapeutic response [ Warnings and Precautions (5.4) ; Drug Interactions (7) ] . Approximately 7% of the population has reduced activity of the CYP2D6 isoenzyme of cytochrome P-450. These individuals are "poor metabolizers" of debrisoquine, dextromethorphan, tricyclic antidepressants, among other drugs. Based on a population PK analysis of Phase 1 studies in healthy subjects, concentrations of tramadol were approximately 20% higher in "poor metabolizers" versus "extensive metabolizers", while M1 concentrations were 40% lower. Concomitant therapy with inhibitors of CYP2D6 such as fluoxetine, paroxetine and quinidine could result in significant drug interactions. In vitro drug interaction studies in human liver microsomes indicate that inhibitors of CYP2D6 such as fluoxetine and its metabolite norfluoxetine, amitriptyline and quinidine inhibit the metabolism of tramadol to various degrees, suggesting that concomitant administration of these compounds could result in increases in tramadol concentrations and decreased concentrations of M1. The full pharmacological impact of these alterations in terms of either efficacy or safety is unknown. Concomitant use of serotonin re-uptake inhibitors and MAO inhibitors may enhance the risk of adverse events, including seizure and serotonin syndrome [see Warnings and Precautions (5.8) and Drug Interactions (7) ] . Excretion Tramadol metabolites are eliminated primarily by the kidneys. Approximately 30% of the dose is excreted in the urine as unchanged drug, whereas 60% of the dose is excreted as metabolites. The remainder is excreted either as unidentified or as unextractable metabolites. Special Populations Hepatic Impairment Metabolism of tramadol and M1 is reduced in patients with severe hepatic impairment based on a study in patients with advanced cirrhosis of the liver, resulting in both a larger area under the concentration time curve for tramadol and longer tramadol and M1 elimination half-lives (13 hrs. for tramadol and 19 hrs. for M1). In patients with severe hepatic impairment, adjustment of the dosing regimen is recommended [see Dosage and Administration (2 )] . Renal Impairment Impaired renal function results in a decreased rate and extent of excretion of tramadol and its active metabolite, M1. In patients with creatinine clearances of less than 30 mL/min, adjustment of the dosing regimen is recommended [see Dosage and Administration (2)] . The total amount of tramadol and M1 removed during a 4-hour dialysis period is less than 7% of the administered dose. Age: Geriatric Healthy elderly subjects aged 65 to 75 years have plasma tramadol concentrations and elimination half-lives comparable to those observed in healthy subjects less than 65 years of age. In subjects over 75 years, maximum serum concentrations are elevated (208 vs. 162 ng/mL) and the elimination half-life is prolonged (7 vs. 6 hours) compared to subjects 65 to 75 years of age. Adjustment of the daily dose is recommended for patients older than 75 years [see Dosage and Administration ( 2.3 )] . Sex The absolute bioavailability of tramadol was 73% in males and 79% in females. The plasma clearance was 6.4 mL/min/kg in males and 5.7 mL/min/kg in females following a 100 mg IV dose of tramadol. Following a single oral dose, and after adjusting for body weight, females had a 12% higher peak tramadol concentration and a 35% higher area under the concentration-time curve compared to males. The clinical significance of this difference is unknown. Poor / Extensive Metabolizers, CYP2D6 The formation of the active metabolite, M1, is mediated by CYP2D6, a polymorphic enzyme. Approximately 7% of the population has reduced activity of the CYP2D6 isoenzyme of cytochrome P450 metabolizing enzyme system. These individuals are "poor metabolizers" of debrisoquine, dextromethorphan and tricyclic antidepressants, among other drugs. Based on a population PK analysis of Phase 1 studies with IR tablets in healthy subjects, concentrations of tramadol were approximately 20% higher in "poor metabolizers" versus "extensive metabolizers," while M1 concentrations were 40% lower Image

12.1 Mechanism of Action Tramadol hydrochloride tablets contain tramadol, an opioid agonist and inhibitor of norepinephrine and serotonin re- uptake. Although the mode of action is not completely understood, the analgesic effect of tramadol is believed to be due to both binding to µ-opioid receptors and weak inhibition of re- uptake of norepinephrine and serotonin. Opioid activity is due to both low affinity binding of the parent compound and higher affinity binding of the O -demethylated metabolite M1 to µ-opioid receptors. In animal models, M1 is up to 6 times more potent than tramadol in producing analgesia and 200 times more potent in µ opioid binding. Tramadol-induced analgesia is only partially antagonized by the opioid antagonist naloxone in several animal tests. The relative contribution of both tramadol and M1 to human analgesia is dependent upon the plasma concentrations of each compound [see Clinical Pharmacology (12.2)] . Analgesia in humans begins approximately within one hour after administration and reaches a peak in approximately two to three hours.

20231121

16

3 DOSAGE FORMS AND STRENGTHS Tramadol Hydrochloride Tablets USP, 50 mg are pale yellow colored, capsule shaped biconvex, film coated tablet debossed with "355" on one side of break line and "U" on the other side of breakline on one side and plain on other side. Tablets: tramadol hydrochloride 50 mg ( 3 ).

Tramadol Hydrochloride Tramadol Hydrochloride TRAMADOL HYDROCHLORIDE TRAMADOL CROSCARMELLOSE SODIUM FERRIC OXIDE YELLOW HYPROMELLOSE 2910 (6 MPA.S) LACTOSE MONOHYDRATE MAGNESIUM STEARATE MICROCRYSTALLINE CELLULOSE POLYETHYLENE GLYCOL 400 SILICON DIOXIDE TITANIUM DIOXIDE pale yellow U;355

13.1 Carcinogenesis, Mutagenesis, Impairment of Fertility Carcinogenesis A slight, but statistically significant, increase in two common murine tumors, pulmonary and hepatic, was observed in an NMRI mouse carcinogenicity study, particularly in aged mice. Mice were dosed orally up to 30 mg/kg in the drinking water (0.36 times the MRHD) for approximately two years, although the study was not done with the Maximum Tolerated Dose. This finding is not believed to suggest risk in humans. No evidence of carcinogenicity was noted in a rat 2-year carcinogenicity study testing oral doses of up to 30 mg/kg in the drinking water, 0.73 times the MRHD. Mutagenesis Tramadol was mutagenic in the presence of metabolic activation in the mouse lymphoma assay. Tramadol was not mutagenic in the in vitro bacterial reverse mutation assay using Salmonella and E. coli (Ames), the mouse lymphoma assay in the absence of metabolic activation, the in vitro chromosomal aberration assay, or the in vivo micronucleus assay in bone marrow. Impairment of Fertility No effects on fertility were observed for tramadol at oral dose levels up to 50 mg/kg in male rats and 75 mg/kg in female rats. These dosages are 1.2 and 1.8 times the maximum recommended human daily dose based on body surface area, respectively.

13 NONCLINICAL TOXICOLOGY 13.1 Carcinogenesis, Mutagenesis, Impairment of Fertility Carcinogenesis A slight, but statistically significant, increase in two common murine tumors, pulmonary and hepatic, was observed in an NMRI mouse carcinogenicity study, particularly in aged mice. Mice were dosed orally up to 30 mg/kg in the drinking water (0.36 times the MRHD) for approximately two years, although the study was not done with the Maximum Tolerated Dose. This finding is not believed to suggest risk in humans. No evidence of carcinogenicity was noted in a rat 2-year carcinogenicity study testing oral doses of up to 30 mg/kg in the drinking water, 0.73 times the MRHD. Mutagenesis Tramadol was mutagenic in the presence of metabolic activation in the mouse lymphoma assay. Tramadol was not mutagenic in the in vitro bacterial reverse mutation assay using Salmonella and E. coli (Ames), the mouse lymphoma assay in the absence of metabolic activation, the in vitro chromosomal aberration assay, or the in vivo micronucleus assay in bone marrow. Impairment of Fertility No effects on fertility were observed for tramadol at oral dose levels up to 50 mg/kg in male rats and 75 mg/kg in female rats. These dosages are 1.2 and 1.8 times the maximum recommended human daily dose based on body surface area, respectively.

ANDA211825

Tramadol Hydrochloride

Tramadol Hydrochloride

29300-355

HUMAN PRESCRIPTION DRUG

ORAL

Label

RECENT MAJOR CHANGES Boxed Warning 09/2023 Indications and Usage ( 1 ) 04/2023 Dosage and Administration ( 2.1 , 2.3 ) 04/2023 Warnings and Precaution ( 5.6 ) 04/2023

17 PATIENT COUNSELING INFORMATION Advise the patient to read the FDA-approved patient labeling (Medication Guide). Storage and Disposal Because of the risks associated with accidental ingestion, misuse, and abuse, advise patients to store tramadol hydrochloride tablets securely, out of sight and reach of children, and in a location not accessible by others, including visitors to the home [see Warnings and Precautions ( 5.1 , 5.17 ), Drug Abuse and Dependence ( 9.2 )] . Inform patients that leaving tramadol hydrochloride tablets unsecured can pose a deadly risk to others in the home. Advise patients and caregivers that when medicines are no longer needed, they should be disposed of promptly. Inform patients that medicine take-back options are the preferred way to safely dispose of most types of unneeded medicines. If no take back programs or Drug Enforcement Administration (DEA)-registered collectors are available, instruct patients to dispose of tramadol hydrochloride tablets by following these four steps: Mix tramadol hydrochloride tablets (do not crush) with an unpalatable substance such as dirt, cat litter, or used coffee grounds; Place the mixture in a container such as a sealed plastic bag; Throw the container in the household trash; Delete all personal information on the prescription label of the empty bottle. Inform patients that they can visit www.fda.gov/drugdisposal for additional information on disposal of unused medicines. Addiction, Abuse, and Misuse Inform patients that the use of tramadol hydrochloride tablets, even when taken as recommended, can result in addiction, abuse, and misuse, which can lead to overdose and death [see Warnings and Precautions (5.1) ] . Instruct patients not to share tramadol hydrochloride tablets with others and to take steps to protect tramadol hydrochloride tablets from theft or misuse. Life-Threatening Respiratory Depression Inform patients of the risk of life-threatening respiratory depression, including information that the risk is greatest when starting tramadol hydrochloride tablets or when the dosage is increased, and that it can occur even at recommended dosages. Educate patients and caregivers on how to recognize respiratory depression and emphasize the importance of calling 911 or getting emergency medical help right away in the event of a known or suspected overdose [see Warnings and Precautions ( 5.3 )] . Accidental Ingestion Inform patients that accidental ingestion, especially by children, may result in respiratory depression or death [see Warnings and Precautions ( 5.3 )] . Interactions with Benzodiazepines and Other CNS Depressants Inform patients and caregivers that potentially fatal additive effects may occur if tramadol hydrochloride tablets are used with benzodiazepines, CNS depressants, including alcohol, or some illicit drugs and not to use these concomitantly unless supervised by a healthcare provider [see Warnings and Precautions ( 5.7 ); Drug Interactions ( 7 )] . Patient Access to Naloxone for the Emergency Treatment of Opioid Overdose Discuss with the patient and caregiver the availability of naloxone for the emergency treatment of opioid overdose, both when initiating and renewing treatment with tramadol hydrochloride tablets. Inform patients and caregivers about the various ways to obtain naloxone as permitted by individual state naloxone dispensing and prescribing requirements or guidelines (e.g., by prescription, directly from a pharmacist, or as part of a community-based program) [see Dosage and Administration ( 2.2 ), Warnings and Precautions ( 5.3 )] . Educate patients and caregivers on how to recognize the signs and symptoms of an overdose. Explain to patients and caregivers that naloxone's effects are temporary, and that they must call 911 or get emergency medical help right away in all cases of known or suspected opioid overdose, even if naloxone is administered [see Overdosage ( 10 )]. If naloxone is prescribed, also advise patients and caregivers: ● How to treat with naloxone in the event of an opioid overdose ● To tell family and friends about their naloxone and to keep it in a place where family and friends can access it in an emergency ● To read the Patient Information (or other educational material) that will come with their naloxone. Emphasize the importance of doing this before an opioid emergency happens, so the patient and caregiver will know what to do. Ultra-Rapid Metabolism of Tramadol and Other Risk Factors for Life-threatening Respiratory Depression in Children Advise caregivers that tramadol hydrochloride tablets are contraindicated in children younger than 12 years of age and in children younger than 18 years of age following tonsillectomy and/or adenoidectomy. Advise caregivers of children ages 12 to 18 years of age receiving tramadol hydrochloride tablets to monitor for signs of respiratory depression [see Warnings and Precautions (5.4) ] . Hyperalgesia and Allodynia Inform patients and caregivers not to increase opioid dosage without first consulting a clinician. Advise patients to seek medical attention if they experience symptoms of hyperalgesia, including worsening pain, increased sensitivity to pain, or new pain [see Warnings and Precautions ( 5.8 ); Adverse Reactions ( 6.2 )] . Maximum single-dose and 24-hour dose Advise patients not to exceed the single-dose and 24-hour dose limit and the time interval between doses, since exceeding these recommendations can result in respiratory depression, seizures and death [see Dosage and Administration ( 2 ); Warnings and Precautions ( 5.3 )] . Serotonin Syndrome Inform patients that opioids could cause a rare but potentially life-threatening condition resulting from concomitant administration of serotonergic drugs. Warn patients of the symptoms of serotonin syndrome, and to seek medical attention right away if symptoms develop. Instruct patients to inform their healthcare provider if they are taking, or plan to take serotonergic medications [ see Warnings and Precautions (5.8) ] . Seizures Inform patients that tramadol hydrochloride tablets may cause seizures with concomitant use of serotonergic agents (including SSRIs, SNRIs, and triptans) or drugs that significantly reduce the metabolic clearance of tramadol [see Warnings and Precautions (5.9) ] . MAOI Interaction Inform patients not to take tramadol hydrochloride tablets while using any drugs that inhibit monoamine oxidase. Patients should not start MAOIs while taking tramadol hydrochloride tablets [see Drug Interactions (7) ] . Important Administration Instructions Instruct patients how to properly take tramadol hydrochloride tablets. [see Dosage and Administration (2) ] . Advise patients not to adjust the dose of tramadol hydrochloride tablets without consulting with a physician or other healthcare professional. Important Discontinuation Instructions In order to avoid developing withdrawal symptoms, instruct patients not to discontinue tramadol hydrochloride tablets without first discussing a tapering plan with the prescriber [see Dosage and Administration ( 2.5 )] . Driving or Operating Heavy Machinery Inform patients that tramadol hydrochloride tablets may impair the ability to perform potentially hazardous activities such as driving a car or operating heavy machinery. Advise patients not to perform such tasks until they know how they will react to the medication [see Warnings and Precautions ( 5.18 )] . Constipation Advise patients of the potential for severe constipation, including management instructions and when to seek medical attention [see Adverse Reactions ( 6 )] . Adrenal Insufficiency Inform patients that opioids could cause adrenal insufficiency, a potentially life-threatening condition. Adrenal insufficiency may present with non-specific symptoms and signs such as nausea, vomiting, anorexia, fatigue, weakness, dizziness, and low blood pressure. Advise patients to seek medical attention if they experience a constellation of these symptoms [see Warnings and Precautions ( 5.11 )] . Hypotension Inform patients that tramadol hydrochloride tablets may cause orthostatic hypotension and syncope. Instruct patients how to recognize symptoms of low blood pressure and how to reduce the risk of serious consequences should hypotension occur (e.g., sit or lie down, carefully rise from a sitting or lying position) [see Warnings and Precautions (5.13) ] . Anaphylaxis Inform patients that anaphylaxis has been reported with ingredients contained in tramadol hydrochloride tablets. Advise patients how to recognize such a reaction and when to seek medical attention [see Contraindications (4) ; Warnings and Precautions (5.16); Adverse Reactions (6) ] . Pregnancy Neonatal Opioid Withdrawal Syndrome Inform female patients of reproductive potential that use of tramadol hydrochloride tablets for an extended period of time during pregnancy can result in neonatal opioid withdrawal syndrome, which may be life-threatening if not recognized and treated. The patient should inform their healthcare provider if they have used opioids at any time during their pregnancy [see Warnings and Precautions (5.5) ; Use in Specific Populations (8.1) ] . E m bryo-Fetal Toxicity Inform female patients of reproductive potential that tramadol hydrochloride tablets may cause fetal harm and to inform the healthcare provider of a known or suspected pregnancy [see Use in Specific Populations (8.1)] . Lactation Advise nursing mothers to carefully observe infants for increased sleepiness (more than usual), breathing difficulties, or limpness. Instruct nursing mothers to seek immediate medical care if they notice these signs [see Use in Specific Populations (8.2 )] . Infertility Inform patients that use of opioids for an extended period of time may cause reduced fertility. It is not known whether these effects on fertility are reversible [see Use in Specific Populations (8.3) ] . Manufactured by: UNICHEM LABORATORIES LTD. Ind. Area, Meerut Road, Ghaziabad – 201 003, India Manufactured for: East Brunswick, NJ 08816 12-R-11/2023 13015155 Image

MEDICATION GUIDE Tramadol Hydrochloride Tablets, USP CIV (tram' a dol hye'' droe klor' ide) Tramadol hydrochloride tablets are : A strong prescription pain medicine that contains an opioid (narcotic) that is used for the management pain in adults, when other pain treatments such as non-opioid pain medicines do not treat your pain well enough or you cannot tolerate them. An opioid pain medicine that can put you at risk for overdose and death. Even if you take your dose correctly as prescribed you are at risk for opioid addiction, abuse, and misuse that can lead to death. Important information about tramadol hydrochloride tablets: Get emergency help or call 911 right away if you take too much tramadol hydrochloride tablets (overdose) . When you first start taking tramadol hydrochloride tablets, when your dose is changed, or if you take too much (overdose), serious or life-threatening breathing problems that can lead to death may occur. Talk to your healthcare provider about naloxone, a medicine for the emergency treatment of an opioid overdose. Taking tramadol hydrochloride tablets with other opioid medicines, benzodiazepines, alcohol, or other central nervous system depressants (including street drugs) can cause severe drowsiness, decreased awareness, breathing problems, coma, and death. Never give anyone else your tramadol hydrochloride tablets. They could die from taking it. Selling or giving away tramadol hydrochloride tablets are against the law. Store tramadol hydrochloride tablets securely, out of sight and reach of children, and in a location not accessible by others, including visitors to the home. Important Information Guiding Use in Pediatric Patients: Do not give tramadol hydrochloride tablets to a child younger than 12 years of age. Do not give tramadol hydrochloride tablets to a child younger than 18 years of age after surgery to remove the tonsils and/or adenoids. Avoid giving tramadol hydrochloride tablets to children between 12 to 18 years of age who have risk factors for breathing problems such as obstructive sleep apnea, obesity, or underlying lung problems. Do not take tramadol hydrochloride tablets if you have: Severe asthma, trouble breathing, or other lung problems. A bowel blockage or have narrowing of the stomach or intestines An allergy to tramadol. Taken a Monoamine Oxidase Inhibitor, MAOI, (medicine used for depression) within the last 14 days. Before taking tramadol hydrochloride tablets, tell your healthcare provider if you have a history of: head injury, seizures liver, kidney, thyroid problems problems urinating pancreas or gallbladder problems abuse of street or prescription drugs, alcohol addiction, opioid overdose, or mental health problems. Tell your healthcare provider if you are: Noticing your pain getting worse. If your pain gets worse after you take tramadol hydrochloride tablets, do not take more of tramadol hydrochloride tablets without first talking to your healthcare provider. Talk to your healthcare provider if the pain that you have increases, if you feel more sensitive to pain, or if you have new pain after taking tramadol hydrochloride tablets. Are pregnant or planning to become pregnant . Use of tramadol hydrochloride tablets for an extended period of time during pregnancy can cause withdrawal symptoms in your newborn baby that could be life- threatening if not recognized and treated. breastfeeding . Not recommended; it may harm your baby. living in a household where there are small children or someone who has abused street or prescription drugs. taking prescription or over-the-counter medicines, vitamins, or herbal supplements. Taking tramadol hydrochloride tablets with certain other medicines can cause serious side effects that could lead to death. When taking tramadol hydrochloride tablets: Do not change your dose. Take tramadol hydrochloride tablets exactly as prescribed by your healthcare provider. Use the lowest dose possible for the shortest time needed. For acute (short-term) pain, you may only need to take tramadol hydrochloride tablets for a few days. You may have some tramadol hydrochloride tablets left over that you did not use. See disposal information at the bottom of this section for directions on how to throw away (dispose of) your unused tramadol hydrochloride tablets. Take your prescribed dose as indicated by your healthcare provider. The maximum dosage is 1 or 2 tablets every 4 to 6 hours, as needed for pain relief. Do not take more than your prescribed dose and do not take more than 8 tablets per day. If you miss a dose, take your next dose at your usual time. Call your healthcare provider if the dose you are taking does not control your pain. If you have been taking tramadol hydrochloride tablets regularly, do not stop taking tramadol hydrochloride tablets without talking to your healthcare provider. Dispose of expired, unwanted, or unused tramadol hydrochloride tablets by taking your drug to an authorized Drug Enforcement Administration (DEA)-registered collector or drug take-back program. If one is not available, you can dispose of tramadol hydrochloride tablets by mixing the product with dirt, cat litter, or coffee grounds; placing the mixture in a sealed plastic bag, and throwing the bag in your trash. Visit www.fda.gov/drugdisposal for additional information on disposal of unused medicines. While taking tramadol hydrochloride tablets DO NOT: Drive or operate heavy machinery, until you know how tramadol hydrochloride tablets affects you. tramadol hydrochloride tablets can make you sleepy, dizzy, or lightheaded. Drink alcohol or use prescription or over-the-counter medicines that contain alcohol. Using products containing alcohol during treatment with tramadol hydrochloride tablets may cause you to overdose and die. The possible side effects of tramadol hydrochloride tablets: constipation, nausea, sleepiness, vomiting, tiredness, headache, dizziness, abdominal pain. Call your healthcare provider if you have any of these symptoms and they are severe. Get emergency medical help or call 911 right away if you have: trouble breathing, shortness of breath, fast heartbeat, chest pain, swelling of your face, tongue, or throat, extreme drowsiness, light-headedness when changing positions, feeling faint, agitation, high body temperature, trouble walking, stiff muscles, or mental changes such as confusion. These are not all the possible side effects of tramadol hydrochloride tablets. Call your healthcare provider for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088. For more information go to dailymed.nlm.nih.gov. Additional medication guides can be obtained by calling Unichem at 1-866- 562-4616. Manufactured by: UNICHEM LABORATORIES LTD. Ind. Area, Meerut Road, Ghaziabad – 201 003, India Manufacturedfor: East Brunswick, NJ 08816 12-R-11/2023 13015155 Image

14 CLINICAL STUDIES Tramadol hydrochloride has been given in single oral doses of 50, 75 and 100 mg to patients with pain following surgical procedures and pain following oral surgery (extraction of impacted molars). In single-dose models of pain following oral surgery, pain relief was demonstrated in some patients at doses of 50 mg and 75 mg. A dose of 100 mg tramadol hydrochloride tended to provide analgesia superior to codeine sulfate 60 mg, but it was not as effective as the combination of aspirin 650 mg with codeine phosphate 60 mg. Tramadol hydrochloride has been studied in three long-term controlled trials involving a total of 820 patients, with 530 patients receiving tramadol hydrochloride. Patients with a variety of chronic painful conditions were studied in double-blind trials of one to three months duration. Average daily doses of approximately 250 mg of tramadol hydrochloride in divided doses were generally comparable to five doses of acetaminophen 300 mg with codeine phosphate 30 mg (TYLENOL with Codeine #3) daily, five doses of aspirin 325 mg with codeine phosphate 30 mg daily, or two to three doses of acetaminophen 500 mg with oxycodone hydrochloride 5 mg (TYLOX) daily. Titration Trials In a randomized, blinded clinical study with 129 to 132 patients per group, a 10-day titration to a daily tramadol hydrochloride dose of 200 mg (50 mg four times per day), attained in 50 mg increments every 3 days, was found to result in fewer discontinuations due to dizziness or vertigo than titration over only 4 days or no titration. In a second study with 54 to 59 patients per group, patients who had nausea or vomiting when titrated over 4 days were randomized to re-initiate tramadol hydrochloride therapy using slower titration rates. A 16-day titration schedule, starting with 25 mg every morning and using additional doses in 25 mg increments every third day to 100 mg/day (25 mg four times per day), followed by 50 mg increments in the total daily dose every third day to 200 mg/day (50 mg four times per day),resulted in fewer discontinuations due to nausea or vomiting and fewer discontinuations due to any cause than did a 10-day titration schedule. Figure 2: Figure 2 Figure 2

8 USE IN SPECIFIC POPULATIONS Pregnancy : May cause fetal harm ( 8.1 ). Lactation : Breastfeeding not recommended ( 8.2 ). 8.1 Pregnancy Risk Summary Use of opioid analgesics for an extended period of time during pregnancy may cause neonatal opioid withdrawal syndrome. Available data with tramadol hydrochloride tablets in pregnant women are insufficient to inform a drug- associated risk for major birth defects and miscarriage. In animal reproduction studies, tramadol administration during organogenesis decreased fetal weights and reduced ossification in mice, rats, and rabbits at 1.4, 0.6, and 3.6 times the maximum recommended human daily dosage (MRHD). Tramadol decreased pup body weight and increased pup mortality at 1.2 and 1.9 times the MRHD [see Data] . Based on animal data, advise pregnant women of the potential risk to a fetus. The estimated background risk of major birth defects and miscarriage for the indicated population is unknown. All pregnancies have a background risk of birth defect, loss, or other adverse outcomes. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2-4% and 15-20%, respectively. Clinical Considerations Fetal/Neonatal Adverse Reactions Use of opioid analgesics for an extended period of time during pregnancy for medical or nonmedical purposes can result in physical dependence in the neonate and neonatal opioid withdrawal syndrome shortly after birth. Neonatal opioid withdrawal syndrome can present as irritability, hyperactivity and abnormal sleep pattern, high pitched cry, tremor, vomiting, diarrhea and failure to gain weight. The onset, duration, and severity of neonatal opioid withdrawal syndrome vary based on the specific opioid used, duration of use, timing and amount of last maternal use, and rate of elimination of the drug by the newborn. Observe newborns for symptoms and signs of neonatal opioid withdrawal syndrome and manage accordingly [see Warnings and Precautions (5.5) ] . Neonatal seizures, neonatal withdrawal syndrome, fetal death and still birth have been reported during post-marketing. Labor or Delivery Opioids cross the placenta and may produce respiratory depression and psycho-physiologic effects in neonates. An opioid antagonist, such as naloxone, must be available for reversal of opioid-induced respiratory depression in the neonate. Tramadol hydrochloride tablets are not recommended for use in pregnant women during or immediately prior to labor, when other analgesic techniques are more appropriate. Opioid analgesics, including tramadol hydrochloride tablets, can prolong labor through actions which temporarily reduce the strength, duration, and frequency of uterine contractions. However, this effect is not consistent and may be offset by an increased rate of cervical dilation, which tends to shorten labor. Monitor neonates exposed to opioid analgesics during labor for signs of excess sedation and respiratory depression. Tramadol has been shown to cross the placenta. The mean ratio of serum tramadol in the umbilical veins compared to maternal veins was 0.83 for 40 women given tramadol during labor. The effect of tramadol hydrochloride tablets, if any, on the later growth, development, and functional maturation of the child is unknown. D ata Animal Data Tramadol has been shown to be embryotoxic and fetotoxic in mice, (120 mg/kg), rats (25 mg/kg) and rabbits (75 mg/kg) at maternally toxic dosages, but was not teratogenic at these dose levels. These doses on a mg/m2 basis are 1.4, 0.6, and 3.6 times the maximum recommended human daily dosage (MRHD) for mouse, rat and rabbit, respectively. No drug-related teratogenic effects were observed in progeny of mice (up to 140 mg/kg), rats (up to 80 mg/kg) or rabbits (up to 300 mg/kg) treated with tramadol by various routes. Embryo and fetal toxicity consisted primarily of decreased fetal weights, decreased skeletal ossification and increased supernumerary ribs at maternally toxic dose levels. Transient delays in developmental or behavioral parameters were also seen in pups from rat dams allowed to deliver. Embryo and fetal lethality were reported only in one rabbit study at 300 mg/kg, a dose that would cause extreme maternal toxicity in the rabbit. The dosages listed for mouse, rat and rabbit are 1.7, 1.9 and 14.6 times the MRHD, respectively. Tramadol was evaluated in pre- and post-natal studies in rats. Progeny of dams receiving oral (gavage) dose levels of 50 mg/kg 1.2 times the MRHD) or greater had decreased weights, and pup survival was decreased early in lactation at 80 mg/kg (1.9 times the MRHD). 8.2 Lactation Risk Summary Tramadol hydrochloride tablets are not recommended for obstetrical preoperative medication or for post-delivery analgesia in nursing mothers because its safety in infants and newborns has not been studied. Tramadol and its metabolite, O -desmethyltramadol (M1), are present in human milk. There is no information on the effects of the drug on the breastfed infant or the effects of the drug on milk production. The M1 metabolite is more potent than tramadol in mu opioid receptor binding [see Clinical Pharmacology (12) ] . Published studies have reported tramadol and M1 in colostrum with administration of tramadol to nursing mothers in the early post-partum period. Women who are ultra-rapid metabolizers of tramadol may have higher than expected serum levels of M1, potentially leading to higher levels of M1 in breast milk that can be dangerous in their breastfed infants. In women with normal tramadol metabolism, the amount of tramadol secreted into human milk is low and dose-dependent. Because of the potential for serious adverse reactions, including excess sedation and respiratory depression in a breastfed infant, advise patients that breastfeeding is not recommended during treatment with tramadol hydrochloride tablets [see Warnings and Precautions (5.4) ] . Clinical Considerations If infants are exposed to tramadol hydrochloride through breast milk, they should be monitored for excess sedation and respiratory depression. Withdrawal symptoms can occur in breastfed infants when maternal administration of an opioid analgesic is stopped, or when breast-feeding is stopped. Data Following a single IV 100 mg dose of tramadol, the cumulative excretion in breast milk within 16 hours post dose was 100 mcg of tramadol (0.1% of the maternal dose) and 27 mcg of M1. 8.3 Females and Males of Reproductive Potential Infertility Use of opioids for an extended period of time may cause reduced fertility in females and males of reproductive potential. It is not known whether these effects on fertility are reversible [see Adverse Reactions (6.2) ] . 8.4 Pediatric Use The safety and effectiveness of tramadol hydrochloride tablets in pediatric patients have not been established. Life-threatening respiratory depression and death have occurred in children who received tramadol [see Warnings and Precautions (5.4) ] . In some of the reported cases, these events followed tonsillectomy and/or adenoidectomy, and one of the children had evidence of being an ultra-rapid metabolizer of tramadol (i.e., multiple copies of the gene for cytochrome P450 isoenzyme 2D6). Children with sleep apnea may be particularly sensitive to the respiratory depressant effects of tramadol. Because of the risk of life-threatening respiratory depression and death: Tramadol hydrochloride tablets are contraindicated for all children younger than 12 years of age [see Contraindications (4) ] . Tramadol hydrochloride tablets are contraindicated for post-operative management in pediatric patients younger than 18 years of age following tonsillectomy and/or adenoidectomy [see Contraindications (4) ] . Avoid the use of tramadol hydrochloride tablets in adolescents 12 to 18 years of age who have other risk factors that may increase their sensitivity to the respiratory depressant effects of tramadol unless the benefits outweigh the risks. Risk factors include conditions associated with hypoventilation such as postoperative status, obstructive sleep apnea, obesity, severe pulmonary disease, neuromuscular disease, and concomitant use of other medications that cause respiratory depression. 8.5 Geriatric Use A total of 455 elderly (65 years of age or older) subjects were exposed to tramadol hydrochloride tablets in controlled clinical trials. Of those, 145 subjects were 75 years of age and older. In studies including geriatric patients, treatment-limiting adverse events were higher in subjects over 75 years of age compared to those under 65 years of age. Specifically, 30% of those over 75 years of age had gastrointestinal treatment-limiting adverse events compared to 17% of those under 65 years of age. Constipation resulted in discontinuation of treatment in 10% of those over 75. Respiratory depression is the chief risk for elderly patients treated with opioids, and has occurred after large initial doses were administered to patients who were not opioid-tolerant or when opioids were co-administered with other agents that depress respiration. Titrate the dosage of tramadol hydrochloride tablets slowly in geriatric patients starting at the low end of the dosing range and frequently reevaluate the patient for signs of central nervous system and respiratory depression [see Warnings and Precautions (5.12) ] . Tramadol is known to be substantially excreted by the kidney, and the risk of adverse reactions to this drug may be greater in patients with impaired renal function. Because elderly patients are more likely to have decreased renal function, care should be taken in dose selection, and it may be useful to monitor renal function. 8.6 Renal and Hepatic Impairment Impaired renal function results in a decreased rate and extent of excretion of tramadol and its active metabolite, M1. In patients with creatinine clearances of less than 30 mL/min, dosing reduction is recommended [see Dosage and Administration ( 2.3 )] . Metabolism of tramadol and M1 is reduced in patients with severe hepatic impairment based on a study in patients with advanced cirrhosis of the liver. In patients with severe hepatic impairment, dosing reduction is recommended [see Dosage and Administration ( 2.3 )] . With the prolonged half-life in these conditions, achievement of steady-state is delayed, so that it may take several days for elevated plasma concentrations to develop.

16 HOW SUPPLIED/STORAGE AND HANDLING Tramadol hydrochloride tablets USP, 50 mg are Pale yellow colored, capsule shaped biconvex, film coated tablet debossed with "355" on one side of break line and "U" on the other side of breakline on one side and plain on other side. Bottles of 100: NDC 29300-355-01 Bottles of 500: NDC 29300-355-05 Bottles of 1,000: NDC 29300-355-10 Store at 20 o to 25 o C (68° to 77°F) [see USP Controlled Room Temperature]. Store tramadol hydrochloride tablets securely and dispose of properly [see Patient Counseling Information ( 17 )]

WARNING: SERIOUS AND LIFE-THREATENING RISKS FROM USE OF TRAMADOL HYDROCHLORIDE TABLETS ADDICTION, ABUSE AND MISUSE Because the use of tramadol hydrochloride tablets exposes patients and other users to the risks of opioid addiction, abuse, and misuse, which can lead to overdose and death, assess each patient's risk prior to prescribing and reassess all patients regularly for the development of these behaviors and conditions [see Warnings and Precautions ( 5.1 )] . LIFE-THREATENING RESPIRATORY DEPRESSION Serious, life-threatening, or fatal respiratory depression may occur with use of tramadol hydrochloride tablets, especially during initiation or following a dose increase. To reduce the risk of respiratory depression, proper dosing and titration of tramadol hydrochloride tablets are essential [see Warnings and Precautions ( 5.2 )] . ACCIDENTAL INGESTION Accidental ingestion of even one dose of tramadol hydrochloride tablets, especially by children, can result in a fatal overdose of tramadol [see Warnings and Precautions ( 5.2 )] . RISKS FROM CONCOMITANT USE WITH BENZODIAZEPINES OR OTHER CNS DEPRESSANTS Concomitant use of opioids with benzodiazepines or other central nervous system (CNS) depressants, including alcohol, may result in profound sedation, respiratory depression, coma, and death. Reserve concomitant prescribing of tramadol hydrochloride tablets and benzodiazepines or other CNS depressants for use in patients for whom alternative treatment options are inadequate [see Warnings and Precautions ( 5.3 ), Drug Interactions ( 7 )] . NEONATAL OPIOID WITHDRAWAL SYNDROME (NOWS) If opioid use is required for an extended period of time in a pregnant woman, advise the patient of the risk of NOWS, which may be life-threatening if not recognized and treated. Ensure that management by neonatology experts will be available at delivery [see Warnings and Precautions ( 5.4 )] . OPIOID ANALGESIC RISK EVALUATION AND MITIGATION STRATEGY (REMS) Healthcare providers are strongly encouraged to complete a REMS-compliant education program and to counsel patients and caregivers on serious risks, safe use, and the importance of reading the Medication Guide with each prescription [see Warnings and Precautions ( 5.5 )] . ULTRA-RAPID METABOLISM OF TRAMADOL AND OTHER RISK FACTORS FOR LIFE-THREATENING RESPIRATORY DEPRESSION IN CHILDREN Life-threatening respiratory Depression and death have occurred in children who received tramadol. Some of the reported cases followed tonsillectomy and/or adenoidectomy; in at least once case, the child had evidence of being an ultra-rapid metabolizer of tramadol due to a CYP2D6 polymorphism [see Warnings and Precautions ( 5.6 )] . Tramadol hydrochloride tablets are contraindicated in children younger than 12 years of age and in children younger than 18 years of age following tonsillectomy and/or adenoidectomy [see Contraindications ( 4 )] . Avoid the use of tramadol hydrochloride tablets in adolescents 12 to 18 years of age who have other risk factors that may increase their sensitivity to the respiratory depressant effects of tramadol [see Warnings and Precautions ( 5.6 )] . INTERACTIONS WITH DRUGS AFFECTING CYTOCHROME P450 ISOENZYMES The effects of concomitant use or discontinuation of cytochrome P450 3A4 inducers, 3A4 inhibitors, or 2D6 inhibitors with tramadol are complex. Use of cytochrome P450 3A4 inducers, 3A4 inhibitors, or 2D6 inhibitors with tramadol hydrochloride tablets requires careful consideration of the effects on the parent drug, tramadol, and the active metabolite, M1 [see Warnings and Precautions ( 5.7 ); Drug Interactions ( 7 )] . WARNING: SERIOUS AND LIFE-THREATENING RISKS FROM USE OF TRAMADOL HYDROCHLORIDE TABLETS See full prescribing information for complete boxed warning. Tramadol hydrochloride tablets expose users to the risks of addiction, abuse and misuse, which can lead to overdose and death. Assess each patient's risk prior to prescribing tramadol hydrochloride tablets, and monitor regularly for these behaviors or conditions. ( 5.1 ) Serious, life-threatening, or fatal respiratory depression may occur. Monitor closely, especially during initiation or following a dose increase. ( 5.3 ) Accidental ingestion of tramadol hydrochloride tablets, especially by children, can result in a fatal overdose of tramadol. ( 5.3 ) Concomitant use of opioids with benzodiazepines or other central nervous system (CNS) depressants, including alcohol, may result in profound sedation, respiratory depression, coma, and death. Reserve concomitant prescribing for use in patients for whom alternative treatment options are inadequate; limit dosages and durations to the minimum required; and follow patients for signs and symptoms of respiratory depression and sedation. ( 5.7 , 7 ) Prolonged use of tramadol hydrochloride tablets, during pregnancy can result in neonatal opioid withdrawal syndrome, which may be life threatening if not recognized and treated If prolonged opioid use is required in a pregnant woman, advise the patient of the risk of neonatal opioid withdrawal syndrome and ensure that appropriate treatment will be available. ( 5.5 ) To ensure that the benefits of opioid analgesics outweigh the risks of addiction, abuse, and misuse, the Food and Drug Administration (FDA) has required a Risk Evaluation and Mitigation Strategy (REMS) for these products. ( 5.2 ) Life-threatening respiratory depression and death have occurred in children who received tramadol. Some of the reported cases followed tonsillectomy and/or adenoidectomy; in at least one case, the child had evidence of being an ultra-rapid metabolizer of tramadol due to a CYP2D6 polymorphism ( 5.4 ). Tramadol hydrochloride tablets are contraindicated in children younger than 12 years of age and in children younger than 18 years of age following tonsillectomy and/or adenoidectomy ( 4 ). Avoid the use of tramadol hydrochloride tablets in adolescents 12 to 18 years of age who have other risk factors that may increase their sensitivity to the respiratory depressant effects of tramadol. ( 5.4 ) The effects of concomitant use or discontinuation of cytochrome P450 3A4 inducers, 3A4 inhibitors, or 2D6 inhibitors with tramadol are complex. Use of cytochrome P450 3A4 inducers, 3A4 inhibitors, or 2D6 inhibitors with tramadol hydrochloride tablets requires careful consideration of the effects on the parent drug, tramadol, and the active metabolite, M1. ( 5.6 , 7 )