Weight Loss Drug
(for more on each weight loss drug, see below)

All medicines have the risks of side effects. For some people, these risks are too great to ever use certain drugs. They can also be expensive. Most weight loss medication studies only looked at one year. After that, there is not as much scientific data on continued weight loss or side effects. The safer and cheaper strategy of diet and exercise should be tried first. Weight loss drug therapy can be considered if a person’s BMI is more than 30 or more than 27 and the person has certain medical conditions.

Weight loss drug therapy is not a cure for being overweight. Once the medicines are stopped, most people gain back the weight they lost. There may also be a maximum effect for each medicine. Once a certain amount of weight is lost, the drugs may not produce any more weight loss.

Below is a table with the  names of weight loss drugs and a brief word on how they work. The average amounts of weight loss for most of the medicines are given where available. For more information, click on each drug’s name.

Brand Names	Generic Name	Average Weight Loss	How It Works
Meridia	Sibutramine*	9.8 lbs in 1 year	Appetite Suppressant
Alli, Xenical	Orlistat*	6.4 lbs in 1 year	Decreases Fat Absorption
Adipex, Ionamin, Fastin	Phentermine*#	7.9 lbs in 6 months	Appetite Suppressant
Tenuate, Dospan	Diethylpropion*#	6.6 lbs in 6 months	Appetite Suppressant
Prozac	Fluoxetine	6.9 lbs in 1 yr	Appetite Suppressant
Zoloft	Sertaline	-	Appetite Suppressant
Paxil, Pexeva	Paroextine	-	Appetite Supressant
Wellbutrin, Budeprion, Buproban, Zyban	Bupropion	6.2 lbs in 6 to 12 months	Appetite Suppressant
Topamax	Topiramate	2.2% to 8% in 6 months to 60 weeks	Unknown
Zonegran	Zonisamide	11 lbs in 16 weeks	Unknown
Glucophage, Fortamet, Glumetza, Riomet	Metformin	4.4 lbs over 2.8 years	Diabetes medicine
Byetta	Exenatide	3.5 to 6.2 lbs in 30 weeks	Diabetes medicine
Symlin	Pramlintide	3 lbs in 1 year or 3.7% in 16 weeks	Curbs appetite and holds food in your stomach longer

Note: Only the medicines with the asterisk (*) are FDA approved for weight loss. The medicines with the number sign (#) have the potential for abuse and are only approved for short term use.

Weight Gain

Just like some of the medicines listed above have weight loss as one of their side effects, some drugs may cause weight gain. It is not a good idea to stop any medicine without first talking with your doctor. Some examples of types of medicines that may cause weight gain are antipsychotics, antidepressants, and some diabetes medicines. You should feel free to talk about this possible side effect with your doctor.

For more information on any drug, you can search for it below. After searching for the drug, select “Patient Education” from the right hand side.

Drug Lookup:

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It is important you discuss any weight loss or exercise plan with your doctor. Only you and your physician can decide what is best for you. Some people have certain conditions that prevent them from doing all exercises, and goal body weights may be different for different people. You need to discuss all these things with your physician before starting any weight loss or exercise program.

This article was written by John Vickery, MD.

References
Ann Intern Med 2005;142:525-531
“Overview of therapy for obesity in adults” UpToDate version 15.3
“Drug therapy of Obesity” UpToDate version 15.3
Treatment Guidelines from the Medical Letter 2008;6:23-28