• Basic Info
• Top Questions
• Interactions

What is phendimetrazine?
Phendimetrazine is a sympathomimetic amine, which is similar to an amphetamine. It is also known as an "anorectic" or "anorexigenic" drug. Phendimetrazine stimulates the central nervous system (nerves and brain), which increases your heart rate and blood pressure and decreases your appetite. Phendimetrazine is used as a short-term supplement to diet and exercise in the treatment of obesity. Phendimetrazine may also be used for purposes other than those listed in this medication guide.

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What are the possible side effects of phendimetrazine?

If you experience any of the following serious side effects, stop taking phendimetrazine 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 phendimetrazine and talk to your doctor if you experience

• restlessness or tremor,

• nervousness or anxiety,

• headache or dizziness,

• insomnia,

• dry mouth or an unpleasant taste in your mouth,

• diarrhea or constipation, or

• impotence or changes in your sex drive.

Phendimetrazine 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.

Side effects other than those listed here may also occur. Talk to your doctor about any side effect that seems unusual or that is especially bothersome.

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How should I take phendimetrazine?
Take phendimetrazine 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. Phendimetrazine is usually taken once a day (sustained release formula) or two to three times daily (immediate-release formula) before meals on an empty stomach. Do not take phendimetrazine in the evening because it may cause insomnia. Do not crush, chew, or open any "once-daily" phendimetrazine tablets or capsules. Swallow them whole.

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What is the most important information I should know about phendimetrazine?
Use caution when driving, operating machinery, or performing other hazardous activities. Phendimetrazine may cause dizziness, blurred vision, or restlessness, and it may hide the symptoms of extreme tiredness. If you experience these effects, avoid hazardous activities. Phendimetrazine 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.

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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.

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What other drugs will affect phendimetrazine?
You cannot take phendimetrazine 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 phendimetrazine. Phendimetrazine 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 phendimetrazine.

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Can I take this if I am pregnant or trying to get pregnant or if I am breastfeeding?

Phendimetrazine has not been formally assigned to a pregnancy category by the FDA. Animal studies have not been reported. There are no controlled data in human pregnancy. Phendimetrazine should only be given during pregnancy when there are no alternatives and benefit outweighs risk.

There are no data on the excretion of phendimetrazine into human milk. The manufacturer recommends that due to the potential for serious adverse reactions in nursing infants, a decision should be made to discontinue nursing or discontinue the drug, taking into account the importance of the drug to the mother.

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What does my medication look like?
Phendimetrazine is available with a prescription under several brand names. The immediate-release formulation is available in 35 mg tablets and capsules. The sustained-release formulation is available in 105 mg capsules. Other brand or generic formulations may also be available. Ask your pharmacist any questions you have about this medication, especially if it is new to you.

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What happens if I overdose?
Seek emergency medical attention. Symptoms of a phendimetrazine overdose include restlessness, tremor, rapid breathing, confusion, hallucinations, panic, aggressiveness, nausea, vomiting, diarrhea, an irregular heartbeat, and seizures.

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Who should not take phendimetrazine?
You cannot take phendimetrazine 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

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Can I stop taking the medication if I feel better?
As a general rule, you should always take your medications exactly as prescribed and do not change the dosage or stop taking the medication without first discussing it with your healthcare provider.

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I am on so many medications; do I have to take them all?
This is called polypharmacy—many different medications being used at the same time by one person. Sometimes, being on multiple medications is acceptable and appropriate but at other times it may be problematic. If you are receiving your medications from multiple physicians you need to ensure that they all know what medications you are taking. The best way to do this is to make a list of all the medications you are currently using, including all nutritional supplements, homeopathic remedies, vitamins and over-the-counter drugs (if possible, also include all the diseases you have been diagnosed with). Give a copy to every doctor who takes care of you so they have it on file, this way they can avoid duplicating medications and perhaps even try to consolidate some. After every doctor's visit remember to update the list accordingly. Also, as much as you possibly can, try to use the same pharmacy to fill all your prescriptions, this way any potential drug interactions can be caught and averted.

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