Bontril (Phendimetrazine) is used in people who are significantly overweight (obese) and have not been able to lose enough weight with diet and exercise alone. Losing weight and keeping it off can reduce the many health risks that come with obesity, including heart disease, diabetes, high blood pressure, and a shorter life.

It is not known how this medication helps people to lose weight. It may work by decreasing your appetite, increasing the amount of energy used by your body, or by affecting certain parts of the brain. This medication is an appetite suppressant and belongs to a class of drugs called sympathomimetic amines.

Use of Bontril

Take the immediate-release form of this medication by mouth, usually 2 to 3 times a day 1 hour before meals or as directed by your doctor. Taking this medication late in the day may cause trouble sleeping (insomnia).

The sustained-release form of phendimetrazine is usually taken once a day 30 - 60 minutes before the morning meal. Swallow this medication whole. Do not crush, chew, or break the capsules. Doing so can destroy the long action of the drug and may increase side effects.

The dosage is based on your medical condition and response to therapy. Your doctor will adjust the dose to find the best dose for you. Use this medication regularly and exactly as prescribed in order to get the most benefit from it. To help you remember, take it at the same time(s) each day.

This medication may cause withdrawal reactions, especially if it has been used regularly for a long time or in high doses. In such cases, withdrawal symptoms (such as depression, severe tiredness) may occur if you suddenly stop using this medication. To prevent withdrawal reactions, your doctor may reduce your dose gradually. Consult your doctor or pharmacist for more details, and report any withdrawal reactions immediately.

Rarely, abnormal drug-seeking behavior (addiction) is possible with this medication. Do not increase your dose, take it more frequently, or use it for a longer time than prescribed. Properly stop the medication when so directed.