Didrex



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Accepted at over 60,000 pharmacies nationwide

Generic Name: benzphetamine
(benz FET ah meen)

What is Didrex?

Didrex 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.

Didrex is used as a short-term supplement to diet and exercise in the treatment of obesity.

Didrex may also be used for purposes other than those listed in this medication guide.

What is the most important information I should know about Didrex?

Use caution when driving, operating machinery, or performing other hazardous activities. Didrex may cause dizziness, blurred vision, or restlessness, and it may hide the symptoms of extreme tiredness. If you experience these effects, avoid hazardous activities.

Didrex is habit forming. You can become physically and psychologically dependent on this medication, and withdrawal effects may occur if you stop taking it suddenly after several weeks of continuous use. Talk to your doctor about stopping this medication gradually.

What should I discuss with my healthcare provider before taking Didrex?

You cannot take Didrex if you

  • have heart disease or high blood pressure
  • have arteriosclerosis (hardening of the arteries)
  • have glaucoma
  • 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
  • diabetes.
  • You may not be able to take Didrex, or you may require a lower dose or special monitoring during treatment if you have any of the conditions listed above.

    Do not take Didrex 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 Didrex passes into breast milk. Do not take benzphetamine without first talking to your doctor if you are breast-feeding a baby.

    How should I take Didrex?

    Take Didrex 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.

    Didrex is usually taken one to three times a day, before meals, on an empty stomach. Follow your doctor's instructions.

    Do not take Didrex in the evening because it may cause insomnia.

    Never take more of this medication than is prescribed for you. Too much Didrex could be very dangerous to your health.

    Store Didrex at room temperature away from moisture and heat.

    What happens if I miss a dose?

    Take the missed dose as soon as you remember. However, if it is almost time for your next dose or if it is already evening, skip the missed dose and take only your next regularly scheduled dose. A dose taken too late in the day will cause insomnia. Do not take a double dose of this medication.

    What happens if I overdose?

    Seek emergency medical attention.

    Symptoms of a Didrex overdose include restlessness, tremor, rapid breathing, confusion, hallucinations, panic, aggressiveness, nausea, vomiting, diarrhea, an irregular heartbeat, and seizures.

    What should I avoid while taking Didrex?

    Use caution when driving, operating machinery, or performing other hazardous activities. Didrex may cause dizziness, blurred vision, or restlessness, and it may hide the symptoms of extreme tiredness. If you experience these effects, avoid hazardous activities.

    Do not take Didrex late in the day. A dose taken too late in the day can cause insomnia.

    What are the possible side effects of Didrex?

    If you experience any of the following serious side effects, stop taking Didrex and seek emergency medical attention:

    • 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 Didrex and talk to your doctor if you experience

  • restlessness or tremor,
  • anxiety or nervousness
  • headache or dizziness,
  • insomnia,
  • dry mouth or an unpleasant taste in your mouth,
  • diarrhea or constipation, or
  • impotence or changes in your sex drive.
  • Didrex is habit forming. You can become physically and psychologically dependent on this medication, and withdrawal effects may occur if you stop taking it suddenly after several weeks of continuous use. Talk to your doctor about stopping this medication gradually.

    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.

    What other drugs will affect Didrex?

    You cannot take Didrex 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 Didrex.

    Didrex 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 Didrex.

    Drugs other than those listed here may also interact with Didrex. Talk to your doctor and pharmacist before taking any prescription or over-the-counter medicines.

    Where can I get more information?

    Your pharmacist has more information about Didrex written for health professionals that you may read.


    Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed

    Every effort has been made to ensure that the information provided by Cerner Multum, Inc. ('Multum') is accurate, up-to-date, and complete, but no guarantee is made to that effect. Drug information contained herein may be time sensitive. Multum information has been compiled for use by healthcare practitioners and consumers in the United States and therefore Multum does not warrant that uses outside of the United States are appropriate, unless specifically indicated otherwise. Multum's drug information does not endorse drugs, diagnose patients or recommend therapy. Multum's drug information is an informational resource designed to assist licensed healthcare practitioners in caring for their patients and/or to serve consumers viewing this service as a supplement to, and not a substitute for, the expertise, skill, knowledge and judgment of healthcare practitioners. The absence of a warning for a given drug or drug combination in no way should be construed to indicate that the drug or drug combination is safe, effective or appropriate for any given patient. Multum does not assume any responsibility for any aspect of healthcare administered with the aid of information Multum provides. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the drugs you are taking, check with your doctor, nurse or pharmacist.