"March 5, 2013 -- A new study adds yet more evidence that the decline in physical activity is contributing to the rise in obesity in the U.S. This study, however, is bound to cause some controversy, as researchers found the increase in obesity in "...
DIDREX (benzphetamine) Tablets 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 was associated with an increased risk of developing pulmonary hypertension, a rare, but often fatal disorder. The use of anorectic agents for longer than three 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. It should be noted that benzphetamine was not specifically studied in this case-control study.
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, DIDREX (benzphetamine) Tablets 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. However, no cases of this valvulopathy have been reported when benzphetamine has been used alone.
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 pre-existing valvular heart diseases or pulmonary hypertension prior to initiation of benzphetamine treatment. DIDREX (benzphetamine) Tablets are 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 DIDREX (benzphetamine) Tablets should be continued only if the patient has satisfactory weight loss within the first 4 weeks of treatment (i.e., weight loss of at least 4 pounds, or as determined by the physician and patient).
When tolerance to the anorectic effect develops, the recommended dose should not be exceeded in an attempt to increase the effect; rather, the drug should be discontinued.
DIDREX (benzphetamine) Tablets are not recommended for severely hypertensive patients or for patients with symptomatic cardiovascular disease including arrhythmias.
DIDREX (benzphetamine) Tablets are not recommended for patients who used any anorectic agents within the prior year.
Insulin requirements in diabetes mellitus may be altered in association with use of anorexigenic drugs and the concomitant dietary restrictions.
Psychological disturbances have been reported in patients who receive an anorectic agent together with a restrictive dietary regime. Caution is to be exercised in prescribing amphetamines for patients with even mild hypertension. The least amount feasible should be prescribed or dispensed at one time in order to minimize the possibility of overdosage.
Carcinogenesis, Mutagenesis, Impairment of Fertility
Animal studies to evaluate the potential for carcinogenesis, mutagenesis or impairment of fertility have not been performed by Pharmacia & Upjohn Company.
Pregnancy Category X (see CONTRAINDICATIONS section).
Amphetamines are excreted in human milk. Mothers taking amphetamines should be advised to refrain from nursing.
Safety and effectiveness in pediatric patients have not been established. Use of benzphetamine hydrochloride is not recommended in individuals under 12 years of age.
Clinical studies of DIDREX (benzphetamine) Tablets did not include sufficient numbers of subjects aged 65 and over to establish safety and efficacy in this population. 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.
Last reviewed on RxList: 2/26/2010
This monograph has been modified to include the generic and brand name in many instances.
Additional Didrex Information
Didrex - User Reviews
Didrex User Reviews
Now you can gain knowledge and insight about a drug treatment with Patient Discussions.
Report Problems to the Food and Drug Administration
You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.
Find out what women really need.