Didrex

Benzphetamine is a stimulant that is similar to an amphetamine. Benzphetamine is an appetite suppressant that affects the central nervous system.

Benzphetamine is used togther with diet and exercise to treat obesity (overweight).

Benzphetamine may also be used for other purposes not listed in this medication guide.

Do not use benzphetamine if you have taken an MAO inhibitor such as furazolidone (Furoxone), isocarboxazid (Marplan), phenelzine (Nardil), rasagiline (Azilect), selegiline (Eldepryl, Emsam), or tranylcypromine (Parnate) in the last 14 days. Serious, life threatening side effects can occur if you use benzphetamine before the MAO inhibitor has cleared from your body.

Taking benzphetamine together with other diet medications (including medicines available over the counter) can cause a rare fatal lung disorder called pulmonary hypertension. Do not take benzphetamine with any other diet medications without your doctor's advice.

You should not take benzphetamine if you are allergic to it, or if you have:

• coronary artery disease (hardening of the arteries);
• heart disease, heart rhythm disorder;
• severe or uncontrolled high blood pressure;
• overactive thyroid;
• glaucoma;
• if you are pregnant;
• if you have a history of drug or alcohol abuse; o
• if you have used any other diet pills within the past year.

If you have any of these other conditions, you may need a benzphetamine dose adjustment or special tests:

• high blood pressure;
• diabetes; or
• a thyroid disorder.

FDA pregnancy category X. This medication can harm an unborn baby or cause birth defects. Do not use benzphetamine if you are pregnant. Tell your doctor right away if you become pregnant during treatment. Use effective birth control while you are using this medication.

Benzphetamine can pass into breast milk and may harm a nursing baby. You should not breast-feed while taking benzphetamine.

Do not give this medication to a child younger than 12 years old.

Benzphetamine may be habit-forming and should be used only by the person it was prescribed for. Never share benzphetamine with another person, especially someone with a history of drug abuse or addiction. Keep the medication in a place where others cannot get to it.

Drinking alcohol can increase certain side effects of benzphetamine.

To prevent sleep problems, avoid taking this medication late in the afternoon.

Benzphetamine may impair your thinking or reactions. Be careful if you drive or do anything that requires you to be alert.

• It is used to treat obesity.

• Store at room temperature.
• Protect from light.
• Store in a dry place. Do not store in a bathroom.
• Keep all drugs in a safe place. Keep all drugs out of the reach of children and pets.
• Check with your pharmacist about how to throw out unused drugs.

Didrex Tablets are contraindicated in patients with advanced arteriosclerosis, symptomatic cardiovascular disease, moderate to severe hypertension, hyperthyroidism, known hypersensitivity or idiosyncrasy to sympathomimetic amines, and glaucoma. Benzphetamine should not be given to patients who are in an agitated state or who have a history of drug abuse.

Hypertensive crises have resulted when sympathomimetic amines have been used concomitantly or within 14 days following use of monoamine oxidase inhibitors. Didrex should not be used concomitantly with other CNS stimulants.

Didrex may cause fetal harm when administered to a pregnant woman. Amphetamines have been shown to be teratogenic and embryotoxic in mammals at high multiples of the human dose. Didrex is contraindicated in women who are or may become pregnant. 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 the fetus.

Didrex 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 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 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 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 Tablets are not recommended for severely hypertensive patients or for patients with symptomatic cardiovascular disease including arrhythmias.

Didrex Tablets are not recommended for patients who used any anorectic agents within the prior year.

Dosage should be individualized according to the response of the patient. The suggested dosage ranges from 25 to 50 mg one to three times daily. Treatment should begin with 25 to 50 mg once daily with subsequent increase in individual dose or frequency according to response. A single daily dose is preferably given in mid-morning or mid-afternoon, according to the patient's eating habits. In an occasional patient it may be desirable to avoid late afternoon administration. Use of benzphetamine hydrochloride is not recommended in individuals under 12 years of age.

Drinking alcohol can increase certain side effects of Didrex.

To prevent sleep problems, avoid taking this medication late in the afternoon.

Didrex may impair your thinking or reactions. Be careful if you drive or do anything that requires you to be alert.

Get emergency medical help if you have any of these signs of an allergic reaction to Didrex: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

Stop using Didrex and call your doctor at once if you have:

• shortness of breath (even with mild exertion), swelling, rapid weight gain;

• chest pain, feeling like you might pass out;

• pounding heartbeats or fluttering in your chest;

• confusion or irritability, unusual thoughts or behavior; or

• dangerously high blood pressure (severe headache, blurred vision, buzzing in your ears, anxiety, confusion, chest pain, shortness of breath, uneven heartbeats, seizure).

Common Didrex side effects may include:

• feeling restless or hyperactive;

• headache, dizziness, tremors;

• sleep problems (insomnia);

• increased sweating;

• dry mouth or an unpleasant taste in your mouth;

• nausea, diarrhea upset stomach; or

• skin rash.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.