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The Skinny on Meridia

March 24, 2000 (Lake Worth, Fla.) -- People have been looking for a safe and effective diet pill ever since two highly effective but potentially dangerous drugs -- fenfluramine (part of the Fen-Phen combination) and Redux --were taken off the market. Meridia (sibutramine) is looking to take their place in the land of weight loss promises, but does it really cut the fat?

A new study from Mexico shows that Meridia is effective, with participants who took the drugs meeting their goal of a 5% loss of total body weight over six months. But a significant number of study participants who took a placebo, or sugar pill, met that goal as well.

The Mexican study, which involved 109 obese patients, is reported in the February issue of the International Journal of Obesity. All the patients were advised to eat a low-calorie, high-carbohydrate, and low-fat diet; half took Meridia and half took the placebo. Researchers looked at the participants' body mass indexes (BMI) and hip-to-waist ratios as well as their weight.

Of those taking Meridia, 85% met their 5% weight loss goal, but 48% of those on the placebo met this goal as well. Still, even those patients remained significantly overweight. They went from an average BMI of 36 to about 32.5. Anyone with a BMI above 27 is considered overweight, and those with BMIs over 30 are classified as obese.

Meridia is an appetite suppressant that helps to curb food cravings. It works through the serotonin system, much as antidepressants do. The study's authors note that the main side effect of Meridia is a dry mouth, although some patients experienced constipation, elevated blood pressure, and a rapid pulse.

"Sibutramine induces significant loss of body weight, BMI and waist [circumference], but does not significantly affect cardiovascular function," the authors write.

This statement concerns Richard Dickey, MD, president of the American Academy of Clinical Endocrinologists. "There have been patients who have had clinically significant rises in blood pressure and pulse with sibutramine," says Dickey, who reviewed the study for WebMD. "Just because these people did a study with 109 patients doesn't mean it doesn't do that."

Patients who take Meridia should have their blood pressure and pulse monitored to see if they have any ill effects from the drug, Dickey says. Overall, he says, it's a safe and effective diet aid that must be used in conjunction with a low-calorie diet, exercise, and behavioral modification.

Mike Myers, MD, who also reviewed the study for WebMD, agrees with Dickey's take on the study. "Sibutramine is not a wonder drug, [but] it does have its place and it can assist with weight loss," he says. "Assist" is the operative word, as diet and exercise are still very important to any weight loss program, both physicians say. Myers is a primary practice physician in Los Alamitos, Calif. A member of the North American Association for the Study of Obesity, he specializes in weight management and eating disorders.