Generic Name: benzphetamine hydrochloride

  • What is Didrex?

    Didrex (benzphetamine) is an appetite suppressant or "anorectic" drug. It stimulates your central nervous system (nerves and brain), which increases you heart rate and blood pressure and decrease your appetite. Didrex is used as a short-term supplement to diet and exercise in the treatment of obesity. It is used as a part of weight-loss plan including a reduced-calorie diet.
  • What is the most important information I should know about Didrex?

    Didrex is habit-forming. You can become physically and psychologically dependent on this medication. Do not exceed the recommended dose. The drug should be gradually discontinued.

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

  • Who should not take Didrex?

    You cannot take Didrex if you have a histoty of drug or alcohol abuse, or if you have any of the following conditions: arteriosclerosis (hardening of the arteries); glaucoma; heart disease; high blood pressure; hyperthyroidism. You cannot start Didrex if you have taken a monoamine oxidase inhibitor (MAOI) such as isocarboxazid (Marplan), tranylcypromine (Parnate), or phenelzine (Nardil) in the last 14 days.

    Didrex is not recommended in children less than 12 years of age.

  • What should I tell my doctor before I take the first dose of Didrex?

    Tell your doctor about all prescription, over-the-counter, and herbal medication you are taking before beginning treatment with Didrex. Also, talk to your doctor about your complete medical history, especially if you have ever had an anxiety disorder, diabetes, epilepsy or another seizure disorder, or problems with your thyroid. If you have any of these conditions, you may not be able to take Didrex, or you may require a lower dose, or special monitoring during treatment.
  • What is the usual dosage?

    The information below is based on the dosage guidelines your doctor uses. Depending on your condition and medical history, your doctor may prescribe a different regimen. Do not change the dosage or stop taking your medication without your doctor's approval.

    Adults: The usual dose range is 25-50 milligrams (mg) one to three times a day.

    CHILD (12 years or older)

    The usual dosage range is 25-50 milligrams once a day, in the mid-morning or mid-afternoon.

  • How should I take Didrex?

    Take Didrex exactly as directed by your doctor. Take each dose with a full glass of water one to three times a day (as prescribed by your doctor), before meals, on an empty stomach. 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 dangerous to your health.
  • What should I avoid while taking Didrex?

    You must not take monoamine oxidase inhibitors (MAOI) such as isocarboxazid (Marplan), tranylcypromine (Parnate), or phenelzine (Nardil) within14 days of beginning Didrex.

    You should avoid CNS stimulants.

  • What are possible food and drug interactions associated with Didrex?

    If Didrex is taken with certain other drugs, the effects of either could be increased, decreased, or altered. It is especially important to check with your doctor before combining Didrex with the following:

    Antihypertensive medications, Guanethidine, Isocarboxazid, Phenelzine, Tranylcyromin, Tricyclic abtidepressants such as amitriptyline

  • What are the possible side effects of Didrex?

    Side effects cannot be anticipated. If any develop or change in intensity, tell your doctor as soon as possible. Only your doctor can determine if it is safe for you to continue taking this drug.

    Side effects may include: Abnormal behavior, anxiety, blurred vision, changes in sex drive, confusion, constipation, diarrhea, dry mouth, elevation of blood pressure, fast and irregular heartbeat, hallucinations, headache, increased heart rate, insomnia, mental or mood changes, nausea, nervousness, palpitation, pounding in the chest, restlessness, severe dizziness, severe excitability, sweating,, unpleasant taste in your mouth

    This is not a complete list of all side effects that may occur. If you have questions or need medical advice about side effects, contact your doctor or health care provider.

  • Can I receive Didrex if I am pregnant or breastfeeding?

    Do not take Didrex if you are pregnant. Didrex 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 breastfeeding a baby.
  • What should I do if I miss a dose of Didrex?

    Take it as soon as you remember, but do not double your dose and do not take it late in the day.
  • How should I store Didrex?

    Store at controlled room temperature.