2001 Annual Meeting of the North American Association for the Study of Obesity

Gary D. Foster, PhD


January 22, 2002

In This Article

Pharmacotherapy for Weight Loss

Pharmacotherapy is becoming increasingly popular as an option in the treatment of obesity. Several investigators provided recent information on the use of the various medications in the management of obesity.

Bupropion is an antidepressant and smoking-cessation medication that may also have some weight-reducing effects. Jain and colleagues[4] reported on a double-blind, multicenter study of bupropion to examine its effect on weight and symptoms of depression. A total of 422 obese adults (body mass index [BMI] 30-44 kg/m2) with mild-to-moderate depression (Beck Depression Inventory scores between 10 and 30) were given a diet that included a 500-kcal/day deficit. Participants were randomized to placebo or bupropion SR (slow release) 300 mg/day (150 mg/day for the first 3 days, followed by 150 mg twice daily). An intent-to-treat analysis revealed that treatment with bupropion resulted in significantly greater weight losses than placebo. Subjects receiving bupropion reduced their weight by 4.6% at 6 months compared with 1.8% for the placebo group (P < .001). There were no differences between the groups in the proportion of subjects with a >= 50% decrease in Beck Depression scores, suggesting no significant effect on mood.

Sibutramine (Meridia) is a combined serotoninergic-noradrenergic reuptake inhibitor that helps to reduce food intake by enhancing feelings of satiety. Sibutramine has been approved by the US Food and Drug Administration (FDA) for weight loss and weight maintenance since 1997. Forty-eight centers in Canada were involved in a nonrandomized open-label study investigating the use of sibutramine in combination with habitual clinic visits for weight control.[5] A total of 470 obese subjects (BMI >= 30 kg/m2) received 10-15 mg of sibutramine daily over 3 months. After 3 months of treatment, there was a 5.9-kg mean weight loss and decreases in fasting plasma triglycerides and total cholesterol. During that same treatment period, 71% of subjects reported adverse events including dry mouth, headache, constipation, influenza-like symptoms, insomnia, pharyngitis, and nausea. In addition, small increases in systolic (1.3 mmHg) and diastolic (1.8 mmHg) blood pressure and heart rate (2.8 bpm) were observed.

Another study presented at the conference examined the effects of sibutramine combined with meal replacements.[6] A total of 151 obese patients (BMI 30-40 kg/m2) are participating in this ongoing 12-month, 2-phase study. In the first phase of the study, participants are given sibutramine plus 2 SlimFast shakes daily (in addition to 1 regular meal) and are counseled on lifestyle modification. Patients who lose >= 5% of their body weight in this first phase (3 months) will continue into the maintenance phase of the program, lasting 9 months. Preliminary analysis of data at 3 months showed that patients experienced a 9.8% mean weight loss, with only 2 patients experiencing a < 5% weight loss. The data suggest that combining pharmacotherapy with meal replacements may increase the amount of short-term weight loss.

Orlistat (Xenical) is an intestinal lipase inhibitor that blocks the absorption of approximately one third of dietary fat. It has been FDA-approved for weight loss and weight loss maintenance since 1999. A study from the National Institutes of Health and Tufts University investigated the use of orlistat in obese adolescents (BMI 44.2 kg/m2) and its effects on levels of weight and fat-soluble vitamins.[7] Because of its mechanism of action, it has the potential to block the absorption of fat-soluble vitamins. In adults, any potential deficiencies can be prevented through the use of daily multivitamins. However, little is known about the effects of orlistat on the vitamin status of adolescents. Serum levels for vitamins A, D, E, and K were measured in 17 obese white and black males and females at baseline and after 3 and 6 months of behavioral treatment combined with a multivitamin and 120 mg of orlistat 3 times per day. After 6 months of treatment, the subjects' mean BMI decreased from 44.2 ± 12.6 to 42.1 ± 13.7 kg/m2, and there were no significant changes in serum levels of vitamin A, E, or K. There was a significant decrease (P < .02) in vitamin D levels following 1 month of treatment, despite multivitamin supplementation. The clinical significance of this decrease is unclear.


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