Prolonged surveillance of dexfenfluramine in severe obesity

Forty-two obese patients entered a placebo-controlled, double-blind 1-year study on dexfenfluramine, a serotonergic anorectic drug. Obesity was severe (mean body mass index 38.4 kg/m2), and of early onset and long duration. A mean of 8 attempts to lose weight was undertaken. After randomisation to 1 year of dexfenfluramine (dF) or placebo (non-dF) treatment, weight losses and changes in health risk indicators were investigated. Thereafter, continued follow-up by physician and dietician was encouraged. Seven patients withdrew, 4 (2 dF, 2 non-dF) because of dissatisfaction. Three patients (2dF, 1 non-dF) failed to lose weight. After initially greater weight losses in dF patients, the mean weight loss after 12 months was not significantly different, i.e. 12.8 kg in the dF vs. 8.6 kg in the non-dF group. Health risk indicators ameliorated to the same extent in both groups. Discontinuation of the active drug resulted in more weight gain [3.24 (dF) vs. 0.82 (non-dF) kg] in the following 2 months. After completion of the 1-year trial and the 2-month drug-free observation period, 8 of the 17 dF patients remained in follow-up for half a year, 5 for 1 year and 3 for 2 years. A respective 61%, 48% and 45% of the weight loss was maintained. The 13, 11 and 10 patients of the placebo group maintained 71%, 37% and 30% of the weight losses at half a year, 1 year and 2 years, respectively. Because of the modest weight loss, dexfenfluramine may not be a break-through in 1-year strategies.(ABSTRACT TRUNCATED AT 250 WORDS)