WARNINGS

Diethylpropion hydrochloride should not be used in combination with other anorectic agents, including prescribed drugs, over-the-counter preparations, and herbal products.

In a case-control epidemiological study, the use of anorectic agents, including diethylpropion, was associated with an increased risk of developing pulmonary hypertension, a rare, but often fatal disorder. The use of anorectic agents for longer than 3 months was associated with a 23-fold increase in the risk of developing pulmonary hypertension. Increased risk of pulmonary hypertension with repeated courses of therapy cannot be excluded.

The onset or aggravation of exertional dyspnea, or unexplained symptoms of angina pectoris, syncope, or lower extremity edema suggest the possibility of occurrence of pulmonary hypertension. Under these circumstances, diethylpropion hydrochloride should be immediately discontinued, and the patient should be evaluated for the possible presence of pulmonary hypertension.

**Valvular heart disease associated with the use of some anorectic agents such as fenfluramine and dexfenfluramine has been reported. Possible contributing factors include use for extended periods of time, higher than recommended dose, and/or use in combination with other anorectic drugs. Valvulopathy has been very rarely reported with diethylpropion hydrochloride monotherapy, but the causal relationship remains uncertain.**The potential risk of possible serious adverse effects such as valvular heart disease and pulmonary hypertension should be assessed carefully against the potential benefit of weight loss. Baseline cardiac evaluation should be considered to detect preexisting valvular heart diseases or pulmonary hypertension prior to initiation of diethylpropion hydrochloride treatment. Diethylpropion hydrochloride is not recommended in patients with known heart murmur or valvular heart disease. Echocardiogram during and after treatment could be useful for detecting any valvular disorders which may occur.

To limit unwarranted exposure and risks, treatment with diethylpropion hydrochloride should be continued only if the patient has satisfactory weight loss within the first 4 weeks of treatment (e.g., weight loss of at least 4 pounds, or as determined by the physician and patient).

Diethylpropion hydrochloride is not recommended for patients who used any anorectic agents within the prior year.

If tolerance develops, the recommended dose should not be exceeded in an attempt to increase the effect; rather, the drug should be discontinued. Diethylpropion hydrochloride may impair the ability of the patient to engage in potentially hazardous activities such as operating machinery or driving a motor vehicle; the patient should therefore be cautioned accordingly.

Prolonged use of diethylpropion hydrochloride may induce dependence with withdrawal syndrome on cessation of therapy. Hallucinations have occurred rarely following high doses of the drug. Several cases of toxic psychosis have been reported following the excessive use of the drug and some have been reported in which the recommended dose appears not to have been exceeded. Psychosis abated after the drug was discontinued.

When central nervous system active agents are used, consideration must always be given to the possibility of adverse interactions with alcohol.

PRECAUTIONS

General

Caution is to be exercised in prescribing diethylpropion hydrochloride for patients with hypertension or with symptomatic cardiovascular disease, including arrhythmias. Diethylpropion hydrochloride should not be administered to patients with severe hypertension.

Reports suggest that diethylpropion hydrochloride may increase convulsions in some epileptics. Therefore, epileptics receiving diethylpropion hydrochloride should be carefully monitored. Titration of dose or discontinuance of diethylpropion hydrochloride may be necessary.

The least amount feasible should be prescribed or dispensed at one time in order to minimize the possibility of overdosage.

Information for Patient

The patient should be cautioned about concomitant use of alcohol or other CNS- active drugs and diethylpropion hydrochloride. (SeeWARNINGS.) The patient should be advised to observe caution when driving or engaging in any potentially hazardous activity.

Laboratory Tests

None.

Drug Interactions

Because diethylpropion hydrochloride is a monoamine, hypertension may result when this agent is used with monoamine oxidase (MAO) inhibitors (see CONTRAINDICATIONS).

Efficacy of diethylpropion with other anorectic agents has not been studied and the combined use may have the potential for serious cardiac problems; therefore, the concomitant use with other anorectic agents is contraindicated.

Antidiabetic drug requirements (i.e., insulin) may be altered. Concurrent use with general anesthetics may result in arrhythmias. The pressor effects of diethylpropion and those of other drugs may be additive when the drugs are used concomitantly; conversely, diethylpropion may interfere with antihypertensive drugs (i.e., guanethidine, α-methyldopa). Concurrent use of phenothiazines may antagonize the anorectic effect of diethylpropion.

Carcinogenesis, Mutagenesis, and Impairment of Fertility

No long-term animal studies have been done to evaluate diethylpropion hydrochloride for carcinogenicity. Mutagenicity studies have not been conducted. Animal reproduction studies have revealed no evidence of impairment of fertility (seePregnancy).

Pregnancy

Teratogenic Effects

**Pregnancy Category B.**Reproduction studies have been performed in rats at doses up to 1.6 times the human dose (based on mg/m 2) and have revealed no evidence of impaired fertility or harm to the fetus due to diethylpropion hydrochloride. There are, however, no adequate and well-controlled studies in pregnant women. Because animal reproduction studies are not always predictive of human response, this drug should be used during pregnancy only if clearly needed.

Spontaneous reports of congenital malformations have been recorded in humans, but no causal relationship to diethylpropion has been established.

Non-teratogenic Effects

Abuse with diethylpropion hydrochloride during pregnancy may result in withdrawal symptoms in the human neonate.

Nursing Mothers

Since diethylpropion hydrochloride and/or its metabolites have been shown to be excreted in human milk, caution should be exercised when diethylpropion hydrochloride is administered to a nursing woman.

Geriatric Use

Clinical studies of diethylpropion hydrochloride did not include sufficient numbers of subjects aged 65 and over to determine whether they respond differently from younger subjects. Other reported clinical experience has not identified differences in responses between the elderly and younger patients. 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.

Pediatric Use

Since safety and effectiveness in pediatric patients below the age of 16 have not been established, diethylpropion hydrochloride is not recommended for use in pediatric patients 16 years of age and under.