Generic Name: benzphetamine (benz FET ah meen)Brand Names: Didrex
Benzphetamine is a sympathomimetic amine, which is similar to an amphetamine. It is also known as an "anorectic" or "anorexigenic" drug. Benzphetamine stimulates your central nervous system (nerves and brain), which increases your heart rate and blood pressure and decreases your appetite.
Benzphetamine is used as a short-term supplement to diet and exercise in the treatment of obesity.
Benzphetamine may also be used for purposes other than those listed in this medication guide.
have heart disease or high blood pressure;
have arteriosclerosis (hardening of the arteries);
have taken a monoamine oxidase inhibitor (MAOI) such as isocarboxazid (Marplan), tranylcypromine (Parnate), or phenelzine (Nardil) in the last 14 days; or
have a history of drug or alcohol abuse.
Before taking this medication, tell your doctor if you have
problems with your thyroid,
an anxiety disorder,
epilepsy or another seizure disorder, or
You may not be able to take benzphetamine, or you may require a lower dose or special monitoring during treatment if you have any of the conditions listed above.Do not take benzphetamine if you are pregnant. Benzphetamine is in the FDA pregnancy category X. This means that benzphetamine will cause birth defects in an unborn baby. It is not known whether benzphetamine passes into breast milk. Do not take benzphetamine without first talking to your doctor if you are breast-feeding a baby.
Take benzphetamine exactly as directed by your doctor. If you do not understand these directions, ask your pharmacist, nurse, or doctor to explain them to you.Take each dose with a full glass of water. Benzphetamine is usually taken one to three times a day, before meals, on an empty stomach. Follow your doctor's instructions.
Do not take benzphetamine in the evening because it may cause insomnia.Never take more of this medication than is prescribed for you. Too much benzphetamine could be very dangerous to your health. Store benzphetamine at room temperature away from moisture and heat.
See also: Benzphetamine dosage in more detail
Symptoms of a benzphetamine overdose include restlessness, tremor, rapid breathing, confusion, hallucinations, panic, aggressiveness, nausea, vomiting, diarrhea, an irregular heartbeat, and seizures.
Do not take benzphetamine late in the day. A dose taken too late in the day can cause insomnia.
an allergic reaction (difficulty breathing; closing of your throat; swelling of your lips, tongue, or face; or hives);
an irregular heartbeat or very high blood pressure (severe headache, blurred vision); or
hallucinations, abnormal behavior, or confusion.
Other, less serious side effects may be more likely to occur. Continue to take benzphetamine and talk to your doctor if you experience
restlessness or tremor,
anxiety or nervousness
headache or dizziness,
dry mouth or an unpleasant taste in your mouth,
diarrhea or constipation, or
impotence or changes in your sex drive.
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.
Usual Adult Dose for Obesity:
Initial dose: 25 to 50 mg once daily in the midmorning or midafternoon Maintenance dose: 25 to 50 mg one to three times daily. Dosage should be individualized based on the patient's needs and response.A single daily dose is preferably given in midmorning or midafternoon, according to the patient's eating habits. It may be desirable to avoid late afternoon administration in some patients.
You cannot take benzphetamine if you have taken a monoamine oxidase inhibitor (MAOI) such as isocarboxazid (Marplan), tranylcypromine (Parnate), or phenelzine (Nardil) in the last 14 days.
Changes in insulin and other diabetes drug therapies may be necessary during treatment with benzphetamine.
Benzphetamine may reduce the effects of guanethidine (Ismelin). This could lead to an increase in blood pressure. Tell your doctor if you are taking guanethidine.
Before taking this medication, tell your doctor if you are taking a tricyclic antidepressant such as amitriptyline (Elavil), amoxapine (Asendin), doxepin (Sinequan), nortriptyline (Pamelor), imipramine (Tofranil), clomipramine (Anafranil), protriptyline (Vivactil), or desipramine (Norpramin). These drugs may decrease the effects of benzphetamine.
Drugs other than those listed here may also interact with benzphetamine. Talk to your doctor and pharmacist before taking any prescription or over-the-counter medicines.