Overview of the Clinical Data

Abstract

Dexfenfluramine, a serotonergic agent, has the ability to produce weight loss and sustained maintenance of the weight loss with continued treatment. A recent review of the efficacy and safety data for dexfenfluramine in 19 double-blind, placebo-controlled clinical trials was conducted. A total of 2297 patients were included in these placebo-controlled studies. Dexfenfluramine patients averaged 151% of their ideal body weight compared with 153% for placebo patients. Mean body mass index (BMI) was 34.2 kg m–2 for dexfenfluramine-treated patients compared with 34.6 kg m–2 for placebo-treated patients. Only two of these 19 studies did not include a prescribed diet; most included a 1200–1600 kcal day–1 diet. Average weight loss ranged from –10.2 to –2.6 kg for dexfenfluramine-treated patients and –6.6 to a gain of +1.3 kg for placebo. Only one of the 19 trials failed to show a statistically significant difference in favor of dexfenfluramine among treatment groups. In all of the longer term studies, a significant difference in weight loss among treatment groups was maintained for 6 and 12 months of treatment. Short-term (<4 months), placebo-controlled, double-blind studies have provided evidence that dexfenfluramine does not adversely affect glycemia, lipid profile, or blood pressure control in obese patients. The most common adverse events associated with dexfenfluramine treatment were diarrhea, asthenia, dry mouth, and somnolence. In summary, dexfenfluramine, as an adjunct to diet, was found to produce significantly more weight loss than placebo for up to 1 year, and common adverse events are generally mild and transient.