Association of Pharmacological Treatments for Obesity With Weight Loss and Adverse Events: A Systematic Review and Meta-analysis.

IMPORTANCE: Five medications have been approved for the management of obesity, but data on comparative effectiveness are limited.

OBJECTIVE: To compare weight loss and adverse events among drug treatments for obesity using a systematic review and network meta-analysis.

DATA SOURCES: MEDLINE, EMBASE, Web of Science, Scopus, and Cochrane Central from inception to March 23, 2016; clinical trial registries.

STUDY SELECTION: Randomized clinical trials conducted among overweight and obese adults treated with US Food and Drug Administration-approved long-term weight loss agents (orlistat, lorcaserin, naltrexone-bupropion, phentermine-topiramate, or liraglutide) for at least 1 year compared with another active agent or placebo.

DATA EXTRACTION AND SYNTHESIS: 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.

MAIN OUTCOMES AND MEASURES: Proportions of patients with at least 5% weight loss and at least 10% weight loss, magnitude of decrease in weight, and discontinuation of therapy because of adverse events at 1 year.

RESULTS: Twenty-eight randomized clinical trials with 29 018 patients (median age, 46 years; 74% women; median baseline body weight, 100.5 kg; median baseline body mass index, 36.1) were included. A median 23% of placebo participants had at least 5% weight loss vs 75% of participants taking phentermine-topiramate (odds ratio [OR], 9.22; 95% credible interval [CrI], 6.63-12.85; SUCRA, 0.95), 63% of participants taking liraglutide (OR, 5.54; 95% CrI, 4.16-7.78; SUCRA, 0.83), 55% taking naltrexone-bupropion (OR, 3.96; 95% CrI, 3.03-5.11; SUCRA, 0.60), 49% taking lorcaserin (OR, 3.10; 95% CrI, 2.38-4.05; SUCRA, 0.39), and 44% taking orlistat (OR, 2.70; 95% CrI, 2.34-3.09; SUCRA, 0.22). All active agents were associated with significant excess weight loss compared with placebo at 1 year-phentermine-topiramate, 8.8 kg (95% CrI, -10.20 to -7.42 kg); liraglutide, 5.3 kg (95% CrI, -6.06 to -4.52 kg); naltrexone-bupropion, 5.0 kg (95% CrI, -5.94 to -3.96 kg); lorcaserin, 3.2 kg (95% CrI, -3.97 to -2.46 kg); and orlistat, 2.6 kg (95% CrI, -3.04 to -2.16 kg). Compared with placebo, liraglutide (OR, 2.95; 95% CrI, 2.11-4.23) and naltrexone-bupropion (OR, 2.64; 95% CrI, 2.10-3.35) were associated with the highest odds of adverse event-related treatment discontinuation. High attrition rates (30%-45% in all trials) were associated with lower confidence in estimates.

CONCLUSIONS AND RELEVANCE: Among overweight or obese adults, orlistat, lorcaserin, naltrexone-bupropion, phentermine-topiramate, and liraglutide, compared with placebo, were each associated with achieving at least 5% weight loss at 52 weeks. Phentermine-topiramate and liraglutide were associated with the highest odds of achieving at least 5% weight loss.