PHENTERMINE HCL

•History of cardiovascular disease (e.g., coronary artery disease, stroke, arrhythmias, congestive heart failure, uncontrolled hypertension) •During or within 14 days following the administration of monoamine oxidase inhibitors •Hyperthyroidism •Glaucoma •Agitated states •History of drug abuse •Pregnancy [see Use in Specific Populations (8.1)] •Nursing [see Use in Specific Populations (8.3)] •Known hypersensitivity, or idiosyncrasy to the sympathomimetic amines

Phentermine Hydrochloride USP has the chemical name of α, α -Dimethylphenethylamine hydrochloride. The structural formula is as follows: 91cf84db-figure-02 Phentermine Hydrochloride is a white, odorless, hygroscopic, crystalline powder which is soluble in water and lower alcohols; slightly soluble in chloroform and insoluble in ether. Phentermine hydrochloride, an anorectic agent for oral administration, is available as: a) powder-filled capsules containing 15 mg Phentermine hydrochloride (equivalent to 12 mg Phentermine) or 30 mg Phentermine hydrochloride (equivalent to 24 mg Phentermine) and inactive ingredients: corn starch, gelatin, lactose monohydrate and magnesium stearate. In addition, the 15 mg capsules contain D&C Yellow #10, FD&C Blue #1, FD&C Red #3, FD&C Red #40, titanium dioxide and the 30 mg capsules contain D&C Yellow #10, FD&C Red #3, titanium dioxide. b) bead-filled capsules containing 30 mg Phentermine hydrochloride (equivalent to 24 mg Phentermine) and inactive ingredients: corn starch, sucrose, hypromellose, povidone, and talc. In addition, the capsule contains FD&C blue #1/Brilliant blue FCF Aluminum Lake, D&C red #28 and gelatin.

Exogenous Obesity Dosage should be individualized to obtain an adequate response with the lowest effective dose. The usual adult dose is 15 mg to 30 mg at approximately 2 hours after breakfast for appetite control. Late evening medication should be avoided because of the possibility of resulting insomnia. Administration of one capsule (30 mg) daily has been found to be adequate in depression of the appetite for 12 to 14 hours. Phentermine is not recommended for use in patients 16 years of age and under. Late evening medication should be avoided because of the possibility of resulting insomnia.

Phentermine Hydrochloride, USP 15 mg and 30 mg is indicated as a short-term (a few weeks) adjunct in a regimen of weight reduction based on exercise, behavioral modification and caloric restriction in the management of exogenous obesity for patients with an initial body mass index ≥30 kg/m2, or≥27 kg/m2 in the presence of other risk factors (e.g., controlled hypertension, diabetes, hyperlipidemia). Below is a chart of Body Mass Index (BMI) based on various heights and weights. BMI is calculated by taking the patient’s weight, in kilograms (kg), divided by the patient’s height, in meters (m), squared. Metric conversions are as follows: pounds ÷ 2.2 = kg; inches x 0.0254 = meters. 91cf84db-figure-01 The limited usefulness of agents of this class, including Phentermine hydrochloride, [see CLINICAL PHARMACOLOGY (12.1, 12.2)] should be measured against possible risk factors inherent in their use such as those described below.

9.1 Controlled Substance Phentermine is a Schedule IV controlled substance. 9.2 Abuse Phentermine is related chemically and pharmacologically to the amphetamines. Amphetamines and other stimulant drugs have been extensively abused and the possibility of abuse of phentermine should be kept in mind when evaluating the desirability of including a drug as part of a weight reduction program. 9.3 Dependence Abuse of amphetamines and related drugs may be associated with intense psychological dependence and severe social dysfunction. There are reports of patients who have increased the dosage of these drugs to many times than recommended. Abrupt cessation following prolonged high dosage administration results in extreme fatigue and mental depression; changes are also noted on the sleep EEG. Manifestations of chronic intoxication with anorectic drugs include severe dermatoses, marked insomnia, irritability, hyperactivity and personality changes. A severe manifestation of chronic intoxication is psychosis, often clinically indistinguishable from schizophrenia.

The least amount feasible should be prescribed or dispensed at one time in order to minimize the possibility of overdosage. 10.1 Acute Overdosage Manifestations of acute overdosage include restlessness, tremor, hyperreflexia, rapid respiration, confusion, assaultiveness, hallucinations, and panic states. Fatigue and depression usually follow the central stimulation. Cardiovascular effects include arrhythmia, hypertension or hypotension, and circulatory collapse. Gastrointestinal symptoms include nausea, vomiting, diarrhea and abdominal cramps. Overdosage of pharmacologically similar compounds has resulted in fatal poisoning usually terminates in convulsions and coma. Management of acute phentermine hydrochloride intoxication is largely symptomatic and includes lavage and sedation with a barbiturate. Experience with hemodialysis or peritoneal dialysis is inadequate to permit recommendations in this regard. Acidification of the urine increases phentermine excretion. Intravenous phentolamine (Regitine®, CIBA) has been suggested on pharmacologic grounds for possible acute, severe hypertension, if this complicates overdosage. 10.2 Chronic Intoxication Manifestations of chronic intoxication with anorectic drugs include severe dermatoses, marked insomnia, irritability, hyperactivity and personality changes. The most severe manifestation of chronic intoxications is psychosis, often clinically indistinguishable from schizophrenia. See Drug Abuse and Dependence (9.3).

7.1 Monoamine Oxidase Inhibitors Use of Phentermine is contraindicated during or within 14 days following the administration of monoamine oxidase inhibitors because of the risk of hypertensive crisis. 7.2 Alcohol Concomitant use of alcohol with phentermine may result in an adverse drug reaction. 7.3 Insulin and Oral Hypoglycemic Medications Requirements may be altered [see Warnings and Precautions (5.9)]. 7.4 Adrenergic Neuron Blocking Drugs Phentermine may decrease the hypotensive effect of adrenergic neuron blocking drugs.

12.1 Mechanism of Action Phentermine is a sympathomimetic amine with pharmacologic activity similar to the prototype drugs of this class used in obesity, amphetamine (d- and dll-amphetamine). Drugs of this class used in obesity are commonly known as “anorectics” or “anorexigenics.” It has not been established that the primary action of such drugs in treating obesity is one of appetite suppression since other central nervous system actions, or metabolic effects, may also be involved. 12.2 Pharmacodynamics Typical of amphetamines include central nervous system stimulation and elevation of blood pressure. Tachyphylaxis and tolerance have been demonstrated with all drugs of this class in which these phenomena have been looked for. 12.3 Pharmacokinetics Following the administration of Phentermine, Phentermine reaches peak concentrations (Cmax) after 3 to 4.4 hours. Specific Populations Renal Impairment Phentermine was not studied in patients with renal impairment. The literature reported cumulative urinary excretion of phentermine under uncontrolled urinary pH conditions is 62% to 85%. Exposure increases can be expected in patients with renal impairment. Use caution when administering phentermine to patients with renal impairment. Drug Interactions In a single-dose study comparing the exposures after oral administration of a combination capsule of 15 mg Phentermine and 92 mg topiramate to the exposures after oral administration of a 15 mg Phentermine capsule or a 92 mg topiramate capsule, there is no significant topiramate exposure change in the presence of Phentermine. However, in the presence of topiramate, Phentermine Cmax and AUC increase 13% and 42%, respectively.

20230418

4

Capsules containing 15 mg and 30 mg Phentermine Hydrochloride

PHENTERMINE HCL PHENTERMINE HCL PHENTERMINE HYDROCHLORIDE PHENTERMINE STARCH, CORN GELATIN LACTOSE MONOHYDRATE D&C YELLOW NO. 10 FD&C BLUE NO. 1 FD&C RED NO. 3 FD&C RED NO. 40 TITANIUM DIOXIDE MAGNESIUM STEARATE K;26

13.1 Carcinogenesis, Mutagenesis, Impairment of Fertility Studies have not been performed with phentermine to determine the potential for carcinogenesis, mutagenesis or impairment of fertility.

ANDA040886

PHENTERMINE HCL

PHENTERMINE HCL

61919-316

HUMAN PRESCRIPTION DRUG

ORAL

316

In relatively short-term clinical trials, adult obese subjects instructed in dietary management and treated with “anorectic” drugs lost more weight on the average than those treated with placebo and diet. The magnitude of increased weight loss of drug-treated patients over placebo-treated patients is only a fraction of a pound a week. The rate of weight loss is greatest in the first weeks of therapy for both drug and placebo subjects and tends to decrease in succeeding weeks. The possible origins of the increased weight loss due to the various drug effects are not established. The amount of weight loss associated with the use of an “anorectic” drug varies from trial to trial, and the increased weight loss appears to be related in part to variables other than the drugs prescribed, such as the physician-investigator, the population treated and the diet prescribed. Studies do not permit conclusions as to the relative importance of the drug and non-drug factors on weight loss. The natural history of obesity is measured over several years, whereas the studies cited are restricted to a few weeks’ duration; thus, the total impact of drug-induced weight loss over that of diet alone must be considered clinically limited.

8.1 Pregnancy Teratogenic Effects Pregnancy category X Phentermine is contraindicated during pregnancy because weight loss offers no potential benefit to a pregnant woman and may result in fetal harm. A minimum weight gain, and no weight loss, is currently recommended for all pregnant women, including those who are already overweight or obese, due to obligatory weight gain that occurs in maternal tissues during pregnancy. Phentermine has pharmacologic activity similar to amphetamine (d- and dll-amphetamine) [see Clinical Pharmacology (12.1)]. Animal reproduction studies have not been conducted with phentermine. If this drug is used during pregnancy, or if the patient becomes pregnant while taking this drug, the patient should be apprised of the potential hazard to a fetus. 8.3 Nursing Mothers It is not known if Phentermine is excreted in human milk; however, other amphetamines are present in human milk. Because of the potential for serious adverse reactions in nursing infants, a decision should be made whether to discontinue nursing or to discontinue the drug, taking into account the importance of the drug to the mother. 8.4 Pediatric Use Safety and effectiveness in pediatric patients have not been established. Because pediatric obesity is a chronic condition requiring long-term treatment, the use of this product, approved for short-term therapy, is not recommended. 8.5 Geriatric Use In general, dose selection for an elderly patient should be cautious, usually starting at the low end of the dosing range, reflecting the greater frequency of decreased hepatic, renal, or cardiac function, and of concomitant disease or other drug therapy. This drug is known to be substantially excreted by the kidney, and the risk of toxic 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 Impairment Phentermine was not studied in patients with renal impairment. Based on the reported excretion of Phentermine in urine, exposure increases can be expected in patients with renal impairment. Use caution when administering Phentermine to patients with renal impairment [see Clinical Pharmacology (12.3)].

Phentermine Hydrochloride capsules, USP are available as follows: Phentermine Hydrochloride capsules, USP 15 mg are supplied as gray opaque cap, rich yellow opaque body with black imprint “K 26” on both the cap and body, filled with powder.