Generic Name: benzphetamine (benz-FET-ah-meen)
Brand Name: Didrex
Didrex is used for:
Short-term (few weeks) management of obesity, as part of a weight-loss plan including a reduced-calorie diet. It may also be used for other conditions as determined by your doctor.
Didrex is an anorectic. Exactly how it works is not known. It may work in part by acting on the appetite center in the brain to cause a temporary reduction in hunger or craving for food.
Do NOT use Didrex if:
- you are allergic to any ingredient in Didrex
- you have had a bad reaction to a sympathomimetic amine (eg, pseudoephedrine)
- you are in an agitated state
- you are pregnant or may become pregnant
- you have glaucoma, an overactive thyroid, moderate to severe or uncontrolled high blood pressure, severe heart blood vessel problems, irregular heartbeat, or certain other heart problems (eg, murmur, heart valve problems)
- you are taking furazolidone, guanadrel, or guanethidine, or you have taken a monoamine oxidase inhibitor (MAOI) (eg, phenelzine) in the past 14 days
- you take other anorectic medicines (eg, amphetamine) or have taken anorectic medicines within the past year
- you have a history of alcohol or other substance abuse
Contact your doctor or health care provider right away if any of these apply to you.
Before using Didrex:
Some medical conditions may interact with Didrex. Tell your doctor or pharmacist if you have any medical conditions, especially if any of the following apply to you:
- if you are pregnant, planning to become pregnant, or are breast-feeding
- if you are taking any prescription or nonprescription medicine, herbal preparation, or dietary supplement
- if you have allergies to medicines, foods, or other substances
- if you have a history of heart problems, blood vessel problems, lung or breathing problems, high blood pressure, diabetes, thyroid problems, or mental or mood problems
Some MEDICINES MAY INTERACT with Didrex. Tell your health care provider if you are taking any other medicines, especially any of the following:
- Furazolidone or MAOIs (eg, phenelzine) because side effects, such as headache, elevated body temperature, or severe high blood pressure, may occur
- Selective serotonin reuptake inhibitors (SSRIs) (eg, fluoxetine) because the risk of side effects, such as mental or mood changes, may be increased
- Urinary acidifiers (eg, ascorbic acid) because they may decrease Didrex's effectiveness
- Stimulants (eg, amphetamine) or urinary alkalinizers (eg, sodium bicarbonate) because they may increase the risk of Didrex's side effects
- Tricyclic antidepressants (eg, amitriptyline) because actions and side effects may be increased by Didrex
- Guanadrel, guanethidine, or other medicines for high blood pressure because their effectiveness may be decreased by Didrex
This may not be a complete list of all interactions that may occur. Ask your health care provider if Didrex may interact with other medicines that you take. Check with your health care provider before you start, stop, or change the dose of any medicine.
How to use Didrex:
Use Didrex as directed by your doctor. Check the label on the medicine for exact dosing instructions.
- Didrex may be taken with or without food.
- If you miss a dose of Didrex, take it as soon as possible. If it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not take 2 doses at once.
Ask your health care provider any questions you may have about how to use Didrex.
Important safety information:
- Didrex may cause drowsiness or dizziness. These effects may be worse if you take it with alcohol or certain medicines. Use Didrex with caution. Do not drive or perform other possibly unsafe tasks until you know how you react to it.
- Do not take more than the recommended dose of Didrex or take for longer than prescribed without checking with your doctor. Doing so may cause serious side effects, including severe heart or lung problems.
- Do not suddenly stop taking Didrex without first talking with your doctor.
- Do not take other prescription medicines, over-the-counter medicines, or herbal supplements to treat obesity without first talking with your doctor.
- Do not use Didrex for any reason or condition other than the one for which it was prescribed.
- Didrex may cause sleeplessness. If you have trouble sleeping, you may need to take Didrex earlier in the day. Talk to your doctor before adjusting your dose of Didrex.
- Diabetes patients - Didrex may affect your blood sugar. Check blood sugar levels closely. Ask your doctor before you change the dose of your diabetes medicine.
- Didrex should not be used in CHILDREN younger than 12 years old; safety and effectiveness in these children have not been confirmed.
- PREGNANCY and BREAST-FEEDING: Do not use Didrex if you are pregnant. If you think you may be pregnant, contact your doctor right away. Didrex is found in breast milk. Do not breast-feed while taking Didrex.
When used for long periods of time or at high doses, some people develop a need to continue taking Didrex. This is known as DEPENDENCE or addiction. When used for long periods of time or at high doses, Didrex may not work as well and may require higher doses to obtain the same effect as when originally taken. This is known as TOLERANCE. Talk with your doctor if Didrex stops working well. Do not take more than prescribed.
If you suddenly stop taking Didrex, you may experience WITHDRAWAL symptoms, such as extreme fatigue, mental depression, or sleep changes.
Possible side effects of Didrex:
All medicines may cause side effects, but many people have no, or minor, side effects. Check with your doctor if any of these most COMMON side effects persist or become bothersome:
Seek medical attention right away if any of these SEVERE side effects occur:
Changes in sex drive; diarrhea; dizziness; dry mouth; headache; nausea; restlessness; sleeplessness; tremor; unpleasant taste.
Severe allergic reactions (rash; hives; itching; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue); blurred vision; chest pain; fainting; fast or irregular heartbeat; mental or mood changes; new or unusual shortness of breath; pounding in the chest; severe excitability; severe or persistent dizziness or headache; swelling of the feet or legs.
This is not a complete list of all side effects that may occur. If you have questions about side effects, contact your health care provider. Call your doctor for medical advice about side effects. To report side effects to the appropriate agency, please read the Guide to Reporting Problems to FDA.
If OVERDOSE is suspected:
Contact 1-800-222-1222 (the American Association of Poison Control Centers), your local poison control center, or emergency room immediately. Symptoms may include confusion; depression; high fever; irregular heartbeat; loss of consciousness; panic; rapid breathing; restlessness; seizures; severe nausea or diarrhea; severe tiredness; stomach cramps; tremor; vomiting.Proper storage of Didrex:
Store Didrex at room temperature, between 68 and 77 degrees F (20 and 25 degrees C). Store away from heat, light, and moisture. Do not store in the bathroom. Keep Didrex out of the reach of children and away from pets.
- If you have any questions about Didrex, please talk with your doctor, pharmacist, or other health care provider.
- Didrex is to be used only by the patient for whom it is prescribed. Do not share it with other people.
- If your symptoms do not improve or if they become worse, check with your doctor.
- Check with your pharmacist about how to dispose of unused medicine.
This information should not be used to decide whether or not to take Didrex or any other medicine. Only your health care provider has the knowledge and training to decide which medicines are right for you. This information does not endorse any medicine as safe, effective, or approved for treating any patient or health condition. This is only a brief summary of general information about Didrex. It does NOT include all information about the possible uses, directions, warnings, precautions, interactions, adverse effects, or risks that may apply to Didrex. This information is not specific medical advice and does not replace information you receive from your health care provider. You must talk with your healthcare provider for complete information about the risks and benefits of using Didrex.
Disclaimer: This information should not be used to decide whether or not to take this medicine or any other medicine. Only your health care provider has the knowledge and training to decide which medicines are right for you. This information does not endorse any medicine as safe, effective, or approved for treating any patient or health condition. This is only a brief summary of general information about this medicine. It does NOT include all information about the possible uses, directions, warnings, precautions, interactions, adverse effects, or risks that may apply to this medicine. This information is not specific medical advice and does not replace information you receive from your health care provider. You must talk with your healthcare provider for complete information about the risks and benefits of using this medicine.