Which weight-loss drugs are effective for treating obesity?
Orlistat, lorcaserin, naltrexone-bupropion, phentermine-topiramate, and liraglutide were effective in achieving weight loss among overweight and obese adults at 52 weeks, a recent study found. Phentermine-topiramate and liraglutide were associated with the highest odds of achieving at least 5 percent weight loss.
To compare weight loss and adverse events among drug treatments for obesity, researchers conducted a systematic review and network meta-analysis of randomized clinical trials (n=28) involving 29,018 patients (median age 46 years; 74 percent women; median baseline body weight 100.5 kg; median baseline body mass index 36.1) treated with US Food and Drug-approved long-term weight loss agents for at least 1 year compared with another active agent or placebo.
Data were collected from MEDLINE, EMBASE, Web of Science, Scopus, and Cochrane Central. Two investigators identified studies and independently abstracted data using a predefined protocol. A Bayesian network meta-analysis was performed and relative ranking of agents was assessed using surface under the cumulative ranking (SUCRA) probabilities. Quality of evidence was assessed using GRADE criteria.
The main outcome measures were proportions of patients with at least 5 percent weight loss and at least 10 percent weight loss, magnitude of decrease in weight, and discontinuation of therapy because of adverse events at 1 year.
A median 23 percent of placebo participants had at least 5 percent weight loss versus 75 percent of participants taking phentermine-topiramate (odds ratio [OR], 9.22; 95 percent CrI, 6.63 to 12.85; SUCRA, 0.95), 63 percent of participants taking liraglutide (OR, 5.54; 4.16 to 7.78; SUCRA, 0.83), 55 percent taking naltrexone-bupropion (OR, 3.96; 3.03 to 5.11; SUCRA, 0.60), 49 percent taking lorcaserin (OR, 3.10; 2.38 to 4.05; SUCRA, 0.39), and 44 percent taking orlistat (OR, 2.70; 2.34 to 3.09; SUCRA, 0.22).
All active agents were associated with significant excess weight loss compared with placebo at 1 year—phentermine-topiramate, 8.8 kg (−10.20 to −7.42 kg); liraglutide, 5.3 kg (−6.06 to −4.52 kg); naltrexone-bupropion, 5 kg (−5.94 to −3.96 kg); lorcaserin, 3.2 kg (−3.97 to −2.46 kg); and orlistat, 2.6 kg (−3.04 to −2.16 kg).
Compared with placebo, liraglutide (OR, 2.95; 2.11 to 4.23) and naltrexone-bupropion (OR, 2.64; 2.10 to 3.35) were associated with the highest odds of adverse event–related treatment discontinuation. High attrition rates (30 to 45 percent in all trials) were associated with lower confidence in estimates.