• Basic Info
• Top Questions
• Interactions

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.

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

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.