Before taking phentermine

Do not take phentermine if you have used an MAO inhibitor such as isocarboxazid (Marplan), phenelzine (Nardil), rasagiline (Azilect), selegiline (Eldepryl, Emsam), or tranylcypromine (Parnate) within the past 14 days. Serious, life-threatening side effects can occur if you take 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.

What is phentermine?

 

Phentermine is a stimulant that is similar to an amphetamine. It is an appetite suppressant that affects the central nervous system.

Phentermine is used togther with diet, exercise and behavioral modification to treat obesity (excessively overweight) in people with risk factors such as high blood pressure, high cholesterol, or diabetes.

Phentermine may also be used for other purposes not listed in this medication guide.

What Is Phentermine Used For?

How Do I Use Phentermine?

Take Phentermine once every day in the morning, half and hour to one hour before your first meal. You may break the tablet or cut it in half. Do not chew up or crush your tablet. Try not to take Phentermine in the afternoon or evening, as it will cause you to have trouble sleeping.

Follow the prescription and instructions your doctor gives you. Do not continue to take Phentermine for a longer period of time than instructed. Also, do not take higher doses than you are told to, as this will only increase possible side effects.

Dosing and administration
Generally, it is recommended by the Food and Drug Administration (FDA) that phentermine should be used short-term (usually interpreted as 'up to 12 weeks'), while following nonpharmacological approaches to weight loss such as healthy dieting and exercise. However, recommendations limiting its use for short-term treatment may be controversial. One reason given behind limiting its use to 12 weeks is drug tolerance, whereby phentermine loses its appetite-suppressing effects after the body adjusts to the drug. On the contrary, it has been shown that phentermine did not lose effectiveness in a 36-week trial. Due to the risk of insomnia, it is generally recommended that the drug be taken either before breakfast or 1-2 hours after breakfast.
 

Phentermine

Tablets

Phentermine works by suppressing your appetite, and, therefore, decreasing your cravings for food you don't need. You should use it along with a specialized phentermine weight loss program to decrease weight. We will do as much as we can to help you meet your weight loss goals. You should improve your diet and increase your health at the same time you're losing weight.

Phentermine is designated chemically as 2-methyl-1-phenylpropan-2-amine and 2-methyl-amphetamine and has the following structural formula:

History

In 1959 phentermine first received approval from the FDA as an appetite suppressing drug. Phentermine hydrochloride then became available in the early 1970s. It was previously sold as Fastin® from King Pharmaceuticals for SmithKline Beecham, however in 1998 it was removed from the market. Medeva Pharmaceuticals sells the name brand of phentermine called Ionamin® and Gate Pharmaceuticals sells it as Adipex-P®. Phentermine is also currently sold as a generic. Since the drug was approved in 1959 there have been almost no clinical studies performed. The most recent study was in 1990 which combined phentermine with fenfluramine or dexfenfluramine and became known as Fen-Phen.

A study was published in 1992 that Fen-Phen was more effective than diet and exercise with few side effects. However, in 1997 after 24 cases of heart valve disease in Fen-Phen users, fenfluramine and dexfenfluramine were voluntarily taken off the market at the request of the FDA. Studies later proved that nearly 30% of people taking fenfluramine or dexfenfluramine had abnormal valve findings. The FDA did not ask manufacturers to remove phentermine from the market.

Phentermine is still available by itself in most countries, including the U.S. However, because it is similar to amphetamines, individuals may develop an addiction to it. Hence, it is classified as a controlled substance in many countries. Internationally, phentermine is a schedule IV drug under the Convention on Psychotropic Substances. In the United States, it is classified as a Schedule IV controlled substance under the Controlled Substances Act.