IN THIS ARTICLE
What should I discuss with my healthcare provider before taking phentermine (Adipex-P, Oby-Cap, T-Diet, Zantryl)?
Do not use phentermine if you have taken an MAO inhibitor such as furazolidone (Furoxone), isocarboxazid (Marplan), phenelzine (Nardil), rasagiline (Azilect), selegiline (Eldepryl, Emsam), or tranylcypromine (Parnate) in the last 14 days. Serious, life threatening side effects can occur if you use phentermine before the MAO inhibitor has cleared from your body.
Taking phentermine together with other diet medications such as fenfluramine (Phen-Fen) or dexfenfluramine (Redux) can cause a rare fatal lung disorder called pulmonary hypertension. Do not take phentermine with any other diet medications without your doctor's advice.
You should not take phentermine if you are allergic to it, or if you have:
If you have any of these other conditions, you may need a phentermine dose adjustment or special tests:
FDA pregnancy category C. It is not known whether phentermine will harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant while using this medication.
Phentermine can pass into breast milk and may harm a nursing baby. You should not breast-feed while taking phentermine.
Do not give this medication to a child younger than 16 years old.
Phentermine may be habit-forming and should be used only by the person it was prescribed for. Never share phentermine with another person, especially someone with a history of drug abuse or addiction. Keep the medication in a place where others cannot get to it.
How should I take phentermine (Adipex-P, Oby-Cap, T-Diet, Zantryl)?
Take exactly as prescribed by your doctor. Do not take in larger or smaller amounts or for longer than recommended. Follow the directions on your prescription label.
It is best to take phentermine on an empty stomach before breakfast or within 2 hours after breakfast.
To prevent sleep problems, take this medication early in the day, no later than 6:00 pm.
Talk with your doctor if you have increased hunger or if you otherwise think the medication is not working properly. Taking more of this medication will not make it more effective and can cause serious, life-threatening side effects.
Phentermine should be taken only for a short time, such as a few weeks.
Do not stop taking phentermine suddenly, or you could have unpleasant withdrawal symptoms. Ask your doctor how to avoid withdrawal symptoms when you stop using phentermine.
Store at room temperature away from moisture and heat.
Keep track of the amount of medicine used from each new bottle. Phentermine is a drug of abuse and you should be aware if anyone is using your medicine improperly or without a prescription.
Report Problems to the Food and Drug Administration
You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.
Need help identifying pills and medications?