Safety and tolerability of new-generation anti-obesity medications: a narrative review

The prevalence of obesity and associated comorbidities is rising. Despite their weight-loss efficacy, new generation anti-obesity medications are only prescribed to a minority of adults with obesity, possibly, which in part may be due to safety concerns. This review presents detailed safety profiles for orlistat, phentermine/topiramate, lorcaserin, naltrexone/bupropion and liraglutide 3.0 mg, and discusses the associated risk-benefit profiles. Two anti-obesity medications presented safety issues that warranted further discussion; phentermine/topiramate (fetal toxicity) and liraglutide 3.0 mg (risk of gallstone disease and mild, acute pancreatitis), whereas the adverse events associated with orlistat, lorcaserin, and naltrexone/bupropion were mostly transient tolerability issues. The difficulties surrounding the objective determination of risk-benefit for anti-obesity medications is discussed. The need for more long-term data, thorough patient assessment, individualization of pharmacological interventions and adherence to stopping rules to maximize risk-benefit are highlighted. Overall, the majority of new generation anti-obesity medications present encouraging tolerability profiles; however, in some cases a lack of long-term clinical trials confounds the accurate determination of risk-benefit.