AHFS DI | Essentials

Benzphetamine (28:20.04) - 382070

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Benzphetamine Hydrochloride

AHFS Class: Amphetamines (28:20.04)

VA Class: GA751
VA Class: CN801
Chemical Name: (+)-N-Benzyl-N,α-dimethylphenethylamine hydrochloride
Molecular Formula: C₁₇H₂₁N•HCl

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View the associated Essentials monograph.

Introduction

Benzphetamine hydrochloride is an amphetamine congener that is used as an anorexigenic agent.

See Uses in the associated General Statement for more information.

Uses

Benzphetamine has been used as an adjunct to caloric restriction in the short-term treatment (a few weeks) of exogenous obesity. The anorexigenic effect of sympathomimetic compounds used in the treatment of obesity is temporary, seldom lasting more than a few weeks and tolerance may occur. However, obesity usually is a chronic disease, and short-term or intermittent therapy with these drugs is unlikely to maintain a long-term benefit;³²⁴ ³³³ ³³⁴ ⁴⁷⁰ ⁴⁷¹ therefore, short-term use of anorexigenic agents, including benzphetamine, is not recommended.⁴⁷⁰ ⁴⁷¹ Furthermore, prolonged administration of benzphetamine in the treatment of obesity is not indicated. To help bring about and maintain loss of weight, the patient must be taught to curtail overeating and to consume a suitable diet. For further information on the treatment of exogenous obesity, see Uses: Exogenous Obesity, in the Amphetamines General Statement 28:20.04.

See Dosage and Administration in the associated General Statement for more information.

Dosage and Administration

Administration

Benzphetamine hydrochloride is administered orally.

Dosage

When benzphetamine hydrochloride is used as an adjunct in the short-term treatment of exogenous obesity, the manufacturers recommend an initial adult dosage of 25–50 mg once daily, preferably given in midmorning or midafternoon according to the patient’s dietary habits; it may be desirable to avoid late afternoon administration in some patients. The manufacturers state that benzphetamine hydrochloride dosage may then be increased, according to individual response and tolerance, to a maximum of 50 mg three times daily.

See Cautions in the associated General Statement for more information.

Cautions

Benzphetamine shares the toxic potentials of amphetamines, and the usual cautions, precautions, and contraindications of amphetamine therapy should be observed. (See Cautions, in the Amphetamines General Statement 28:20.04.)

Nervous System Effects

Adverse nervous system effects of benzphetamine may include overstimulation, restlessness, tremor, dizziness, sweating, headache, and insomnia. Psychologic disturbances have occurred in patients receiving anorexigenic agents combined with dietary restrictions. Rarely, psychotic episodes have occurred in patients receiving recommended dosages of benzphetamine. Mental depression may occur following discontinuance of the drug.

GI Effects

GI effects of benzphetamine may include dryness of the mouth, unpleasant taste, nausea, vomiting, diarrhea, and other GI disturbances.

Cardiovascular Effects

Palpitation, tachycardia, and increased blood pressure may occur in patients receiving benzphetamine. Pulmonary hypertension and cardiomyopathy, usually manifested as ventricular hypertrophy and/or congestive heart failure, have occurred in patients receiving amphetamines chronically (e.g., chronic abusers) and is potentially fatal; the cardiomyopathy is similar to adrenergic cardiomyopathies (e.g., that associated with pheochromocytoma).

Other Adverse Effects

Urticaria, allergic skin reactions, and changes in libido may occur in patients receiving benzphetamine.

Precautions and Contraindications

Patients should be warned that benzphetamine may impair their ability to perform activities requiring mental alertness or physical coordination (e.g., operating machinery, driving a motor vehicle). Benzphetamine should be used with caution in patients with mild hypertension, and blood pressure should be closely monitored.

Habituation or addiction has been reported with similar drugs and the possibility of its occurrence should be considered with benzphetamine. (See Chronic Toxicity in the Amphetamines General Statement 28:20.04.)

Benzphetamine is contraindicated in patients with advanced arteriosclerosis, hyperthyroidism, moderate to severe hypertension, symptomatic cardiovascular disease, agitated states, a history of drug abuse, glaucoma, or known hypersensitivity or idiosyncrasy to sympathomimetic amines. In addition, the drug is contraindicated during or within 14 days of administration of monoamine oxidase inhibitors.

Pediatric Precautions

Use of benzphetamine in children younger than 12 years of age is not recommended.

Pregnancy and Lactation

Pregnancy

Benzphetamine may cause fetal toxicity when administered to pregnant women. Since the risks clearly outweigh any possible benefits in women who are or may become pregnant, the drug is contraindicated in such women. If benzphetamine is administered during pregnancy or if the patient becomes pregnant while receiving the drug, the patient should be informed of the potential hazard to the fetus.

Lactation

It is not known whether benzphetamine is distributed into milk, but other amphetamines have been shown to distribute into milk. Because of the potential for serious adverse reactions to benzphetamine in nursing infants, women receiving the drug should not nurse their infants.

See Acute Toxicity in the associated General Statement for more information.

See Pharmacology in the associated General Statement for more information.

Pharmacology

Benzphetamine apparently produces an anorexigenic effect and loss of weight. As with other amphetamine derivatives, no primary effect on appetite has been demonstrated with benzphetamine and it is probable that its anorexigenic effect is secondary to CNS stimulation.

See Pharmacokinetics in the associated General Statement for more information.

Pharmacokinetics

Benzphetamine is readily absorbed from the GI tract and effects persist for about 4 hours after oral administration.

See Chemistry and Stability in the associated General Statement for more information.

Chemistry and Stability

Chemistry

Benzphetamine hydrochloride is an amphetamine congener that is used as an anorexigenic agent. The drug occurs as a white, crystalline powder and is soluble in water and in alcohol.

Stability

Benzphetamine hydrochloride tablets should be stored in tight containers at 15–30°C.

For further information on chemistry, pharmacology, pharmacokinetics, uses, cautions, chronic toxicity, acute toxicity, and dosage and administration of amphetamines, see the Amphetamines General Statement 28:20.04.

Preparations

Benzphetamine hydrochloride is subject to control under the Federal Controlled Substances Act of 1970 as a schedule III (C-III) drug.

Benzphetamine Hydrochloride

Routes Forms Strengths Brand Names Manufacturer

Oral
Tablets

50 mg

Didrex^® (C-III; with povidone, scored)
Pfizer

Tablets, film-coated

50 mg

Benzphetamine Hydrochloride ( C-III)
Paddock

Comparative Pricing

This pricing information is subject to change at the sole discretion of DS Pharmacy. For the most current and up-to-date pricing information, please visit www.drugstore.com.

Benzphetamine HCl 50MG Tablets (BOCA PHARMACAL): 30/$39.99 or 90/$111.96

Didrex 50MG Tablets (PFIZER U.S.): 90/$137.98 or 180/$265.99