VA Class:GA751

AHFS Class:

• Amphetamine Derivatives 28:20.08.04

Generic Name(s):

• Diethylpropion Hydrochloride

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

Diethylpropion is 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. To help bring about and maintain loss of weight, the patient must be taught to curtail overeating and to consume a suitable diet. As with other anorexigenic agents, prolonged administration of diethylpropion is not indicated.

Administration

Diethylpropion hydrochloride is administered orally.

Dosage

The recommended adult dosage of diethylpropion hydrochloride is 25 mg 3 times daily 1 hour before meals; an additional 25 mg may be given in midevening if necessary. The extended-release tablet containing 75 mg of the drug may be given once daily, in midmorning. When tolerance to the anorexigenic effect of diethylpropion develops, the recommended dosage should not be exceeded in an attempt to increase the effect, but instead the drug should be discontinued.

Nervous System Effects

Adverse nervous system effects of diethylpropion may include overstimulation, nervousness, restlessness, jitteriness, anxiety, insomnia, dizziness, euphoria, dysphoria, mental depression, headache, tremor, and blurred vision. Rarely, psychotic episodes may occur in patients receiving recommended dosages. An increase in seizures has occurred in some patients with epilepsy who received the drug.

Cardiovascular Effects

Palpitation, tachycardia, increased blood pressure, precordial pain, and arrhythmia have occurred in patients receiving diethylpropion.

GI Effects

Adverse GI effects of diethylpropion may include unpleasant taste, dryness of the mouth, nausea, vomiting, abdominal discomfort, diarrhea, and constipation.

Other Adverse Effects

Other adverse effects of diethylpropion include urticaria, rash, ecchymosis, erythema, impotence, changes in libido, menstrual irregularity, bone marrow depression, leukopenia, agranulocytosis, dyspnea, hair loss, muscle pain, dysuria, and polyuria.

Precautions and Contraindications

Patients should be warned that diethylpropion may impair their ability to perform hazardous activities requiring mental alertness or physical coordination (e.g., operating machinery, driving a motor vehicle). The drug should be used with caution in patients with hypertension or symptomatic cardiovascular disease, including arrhythmias. Diethylpropion should also be used with caution in patients with epilepsy, since the drug has been reported to increase seizures in some epileptics.

Habituation or addiction has occurred with similar drugs and the possibility of its occurrence should be considered with diethylpropion.

Diethylpropion is contraindicated in patients with hyperthyroidism, advanced arteriosclerosis, agitated states, severe hypertension, 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

Diethylpropion is not recommended for use in children younger than 12 years of age.

Pregnancy and Lactation

Pregnancy

Safe use of diethylpropion during pregnancy has not been established. During pregnancy it is questionable whether potential benefits from anorexigenic agents outweigh potential risks and this condition should probably be considered a contraindication to their use, especially during the first trimester.

Lactation

Since diethylpropion hydrochloride and/or its metabolites are excreted into milk in humans, the drug should be used with caution in nursing women.

Insulin requirements in patients with diabetes mellitus may be decreased in association with the use of diethylpropion and the concomitant dietary regimen and weight loss; therefore, diethylpropion should be administered with caution in patients with diabetes mellitus.

Like amphetamines, diethylpropion may decrease the hypotensive effect of guanethidine.

Pharmacology

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

Pharmacokinetics

Diethylpropion is readily absorbed from the GI tract and its effects persist for about 4 hours after oral administration of conventional tablets.

Chemistry and Stability

Chemistry

Diethylpropion hydrochloride is an amphetamine congener that is used as an anorexigenic agent. The drug occurs as a white to off-white, fine crystalline powder that is odorless or has a slight characteristic odor and is freely soluble in water and in alcohol.

Stability

Diethylpropion hydrochloride is hygroscopic and should be protected from moisture; aqueous solutions are unstable. Commercially available diethylpropion hydrochloride tablets and extended-release tablets should be stored in tight containers at room temperature, preferably at a temperature less than 30°C.