A COMPARISON OF SIBUTRAMINE AND DEXFENFLURAMINE IN THE TREATMENT OF OBESITY

Objective: Because long-term weight reduction is often unsuccessful wi th dietary restriction alone, pharmacological agents have been used to promote weight loss. We have compared the novel (multiple monoamine n eurotransmitter reuptake inhibitor) antiobesity drug sibutramine (10 m g once daily) with the extensively studied serotonin-releaaing antiobe sity agent dexfenfluramine (15 mg twice daily). Research Methods and P rocedures: 226 healthy outpatients (aged 18 to 65 years; body mass ind ex greater than or equal to 27 kg/m(2)) were included in a 12-week, ra ndomized, double-blind, parallel group study. The main outcome measure s were changes in weight, body mass index, waist and hip circumference and ratio, and safety profiles. Results: Mean (+/-SEM) absolute weigh t loss was 4.5 +/- 0.4 kg in the sibutramine group (n = 112) and 3.2 /- 0.3 :kg in the dexfenfluramine group (n = 112) (endpoint analysis); 4.7 +/- 0.4 kg in the sibutramine group (n = 94); and 3.6 +/- 0.3 kg in the dexfenfluramine group (n = 94) (completers analysis). Comparing the two treatments under the conventional null hypothesis of equality as a secondary analysis, weight loss at endpoint in patients receivin g sibutramine was significantly greater than that achieved with dexfen fluramine (p<0.05). Both drugs had similar adverse events profiles: 17 4 patients (77%) experienced adverse events; 17 patients withdrew du t o adverse events (sibutramine, n = 6; dexfenfluramine, n = 11). Pulse rate increased significantly in sibutramine-treated patients (3.6 bpm) , but decreased in dexfenfluramine-treated patients (-0.9 bpm). Discus sion: Sibutramine (10 mg once daily) is at least as effective as dexfe nfluramine (15 mg twice daily) in achieving weight loss in patients wi th obesity.