Whether the treatment of obesity requires medication is a decision that must be made on a case-by-case basis. Drug therapy was never intended to be anything but a last-choice option when no other treatment had worked. And today, the use of medications to help suppress appetite or otherwise alter the body's energy balance remains a controversial area in obesity management. Drugs should be used only in people whose BMI exceeds 30 or exceeds 27 when accompanied by serious medical conditions that could be improved by weight loss. Anorectics--drugs that reduce appetite--do not magically melt away pounds: While they may make it easier to adhere to lifestyle changes, they do not eliminate the need to alter behavior permanently.
For good results, drug therapy must be combined with extensive dietary, exercise, and behavior modifications. Anorectics are not effective for everyone. For example, people whose excessive eating is triggered by habits, stress, or emotions may benefit less from drugs that reduce appetite than those who eat because of hunger. If no weight is lost in the first week or two of use, the drug is unlikely to help and should be discontinued (consult your doctor first). Following are the types of drugs currently in use:
Antidepressants. Although the Food and Drug Administration has not approved antidepressants for the treatment of obesity, patients taking the selective serotonin reuptake inhibitors fluoxetine (Prozac) or sertraline (Zoloft) for depression often experience weight loss. Typically, doctors prescribe these drugs for weight loss if the patient is also depressed. SSRIs increase brain levels of serotonin, which produces feelings of fullness. Thus, some patients taking SSRIs feel less hungry, are less concerned with food, and are better able to control their appetites, though the effect may not last long.
Lipase inhibitor. Orlistat (Xenical) blocks the intestinal absorption of about 30 percent of dietary fat. Side effects--such as cramping, oily anal leakage, and explosive diarrhea--tend to be worse when patients eat greater quantities of fatty foods. These adverse effects discourage the consumption of such foods and contribute to the effectiveness of the drug. Because fat malabsorption associated with orlistat can lead to a loss of fat-soluble vitamins A, D, E, and K in the stools, a multivitamin must be taken with this medication.
Noradrenergics. These drugs increase levels of norepinephrine (noradrenaline) in the brain. Norepinephrine reduces appetite by stimulating the central nervous system. On average, people taking a noradrenergic lose about 1/2 pound more per week than those taking a placebo. A noradrenergic agent called phenylpropanolamine, present in several medicines and over-the-counter appetite suppressants such as Dexatrim, was recalled by the FDA in November 2000.
Serotonin/norepinephrine reuptake inhibitor. The drug sibutramine (Meridia) enhances both serotonin and norepinephrine levels in the brain. This action promotes feelings of fullness and thus reduces appetite. Studies show that patients who took sibutramine while on a reduced-calorie diet showed significant weight loss during the first six months of treatment. In addition, significant weight loss was maintained for one year. Because of the potential for adverse effects, such as increased blood pressure, sibutramine has come under increased scrutiny. Additional research is currently underway to evaluate the safety of this drug.
