THE EFFECT OF WITHDRAWAL AND REINTRODUCTION OF DEXFENFLURAMINE IN THETREATMENT OF OBESITY

In this study 25 patients, who had completed the INDEX trial (Guy-Gran d at al. Lancet 1989; 2: 1142-1145) were reexamined 2 months after wit hdrawal of the study medication. The patients then in an open trial re ceived dexfenfluramine (dF) for 6 months. The observed weight gain aft er withdrawal of study medication was higher in patients treated befor ehand with dF (2.6+/-1.2 kg) than in patients who had received placebo (0.8+/-1.0 kg). In the open dF trial rate of weight loss was lower th an it had initially been in the patients receiving dF from the outset of the INDEX trial (13.1+/-4.6 kg within 6 months). In the previous dF treated patients weight loss after re-introduction of dF was 3.7+/-2. 7 kg. The previous placebo-treated patients, now receiving dF for the first time, lost 4.8+/-1.1 kg. Thus, after withdrawal of dF, patients experience weight gain, but after re-introduction of dF, renewed weigh t loss is achieved. However, the rate of weight loss declines with tim e.