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Medication in the Treatment of Obesity (cont.)

How Medication Can Help You Lose Weight

With one exception, the medications used to treat obesity work by suppressing the appetite.

  • Appetite suppressants decrease appetite by increasing levels of serotonin or catecholamines, such as norepinephrine. Serotonin and catecholamines are brain chemicals that affect mood and appetite.
  • The exception, Xenical, works by disrupting lipase, the enzyme in the intestines that controls absorption of fats. It prevents digestion of about 30% of the fats eaten. These undigested fats are not absorbed, but excreted, thus lowering the calorie intake.

These medications work best if used in conjunction with lifestyle changes such as eating less and increasing physical activity. Research studies conducted in people with obesity all show that people who eat less, increase physical activity, and take medication lose considerably more weight than people who use medication without making lifestyle changes.

Like all drugs, those used to treat obesity may have powerful side effects and other undesirable risks.

  • Prescription weight-loss medications should be used only under the care of a medical professional and only by people who are at high risk of obesity-related health problems.
  • This usually means people with a BMI of 30 or greater or those with a BMI of 27 or greater who have other risk factors such as high blood pressure or high cholesterol.
  • These medications should not be used for relatively minor or cosmetic weight loss.

Some physicians have experimented with combining weight-loss drugs.

  • Some have combined a weight-loss drug with another type of drug such as a selective serotonin-reuptake inhibitor (SSRI), a class of antidepressants that includes fluoxetine (Prozac) and sertraline (Zoloft).
  • This is called "off label" use because these combinations have not been approved by the U.S. Food and Drug Administration (FDA) for obesity.
  • Little information is available about the safety or effectiveness of these combinations.

Traditional weight-loss medications were approved for only a few weeks or months of use. The newer medications now in use may be used for longer periods. These drugs are still being studied to see whether they have any long-term side effects.

Medically Reviewed by a Doctor on 4/23/2015
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