WEIGHT LOSS: MERIDIA & NEW PRESCRIPTION DRUGS
Question: I am interested in losing weight, and I recently heard that there are new diet drugs on the market. Do these drugs really work? How safe are they? How can I tell if they are appropriate for me?
Answer: The US Food and Drug Administration (FDA) recently approved new diet drugs for long-term use. The first, Sibutramine (Meridia), works by suppressing the appetite. Sibutramine works by slowing down the clearance of chemicals in the brain, norepinephrine and serotonin, that affect appetite. Dexfenfluramine (Redux) also slows down the clearance of serotonin; however, unlike Sibutramine, dexfenfluramine causes an increase in the release of serotonin as well. Dexfenfluramine was recently taken off the market because of concerns over its potential effects on heart valves. Because Sibutramine does not increase the release of serotonin, it is unlikely to cause heart valve damage.
When used in combination with a low-calorie diet in one study, patients on Sibutramine lost an average of 10-14 pounds over the course of a year compared with 3.5 pounds with diet alone. Common side effects of taking Sibutramine include dry mouth, headache, constipation, nausea, dizziness, and insomnia. In a small number of patients, this drug can also cause an increase in blood pressure, so people with uncontrolled blood pressure are discouraged from taking it.
The second diet drug recently approved for long-term use is Orlistat (Xenical). Orlistat works by preventing the digestive system from digesting and absorbing fat. In general, studies show that over the course of a year, patients taking Orlistat can lose an additional 6-10 pounds more when compared to those who are on diet alone. The major side effects of Orlistat include oily spotting, gas, diarrhea, and bowel incontinence. Because Orlistat may also decrease the absorption of certain vitamins, it is recommended that patients take supplements containing vitamins A, D, E, and K.
To lose weight and keep weight off with these drugs requires lifelong treatment. Therefore, the decision to start diet drug treatment is a serious one and should be made together with a doctor with whom you plan to maintain an ongoing relationship. These drugs are currently recommended only for patients whose weight poses a serious medical risk and should be used with a well-balanced and reduced-calorie diet. Although these drugs are approved for long-term use, researchers have studied patients for only 1-2 years. These drugs, however, are not believed to cause heart valve problems or serious lung disease.
