The selective cannabinoid-receptor blocker rimonabant produces sustained weight loss and improvement in several metabolic parameters. To further explore the effects of rimonabant, industry-supported investigators randomized 1036 overweight or obese adults (body-mass index, 27–40 kg/m2) with dyslipidemia to receive low- or high-dose rimonabant (5 or 20 mg daily) or placebo for 12 months, in addition to following a hypocaloric diet.
In intent-to-treat analyses, benefits were clearest with high-dose rimonabant. Compared with the placebo group, the high-dose group exhibited significantly greater mean weight loss (–6.7 kg), reduction in waist circumference (–5.8 cm), increase in HDL cholesterol levels (+10.0%), and reduction in triglyceride levels (–13.0%); small but significant reductions in blood pressure and C-reactive protein levels also were noted, as were increased levels of adiponectin — a recently discovered cardioprotective molecule. The frequency of adverse events was similar in the three groups, although no tests of statistical significance are reported. Only about 60% of patients in each group completed the study; no reason other than "patient request" is given for nearly half of discontinuations.
Rimonabant seems to be about as effective as several currently available drugs in achieving substantial weight loss during a 1-year period. It also produces beneficial physiologic and metabolic changes. Still, we do not know whether rimonabant or other weight loss drugs improve long-term health outcomes — and, as happened with "phen-fen," adverse outcomes could emerge with longer use.
Reference:
Després J-P et al. Effects of rimonabant on metabolic risk factors in overweight patients with dyslipidemia. N Engl J Med 2005 Nov 17; 353:2121-34.