Drugs for Treating Obesity

Older medications approved for chronic weight management (orlistat, naltrexone/bupropion, liraglutide 3 mg and, in the USA, phentermine/topiramate) have not been widely adopted by health care providers. Those medications produce only modest additional weight loss when used to augment lifestyle intervention. However, semaglutide 2.4 mg weekly has recently emerged and produces much more weight loss – on average 15% weight loss at 1 year. Semaglutide’s enhanced efficacy and that its class (GLP-1 receptor analogs) is well-known may result in more clinicians adopting pharmacotherapy. Furthermore, the first dedicated cardiovascular outcome trial powered for superiority testing an anti-obesity medication (SELECT) is underway with semaglutide 2.4 mg. A positive outcome will further promote the concept that weight management should be a primary target for cardiometabolic disease control. In phase 3, tirzepatide and cagrilintide/semaglutide combination are showing promise for even greater weight loss efficacy. Another recently approved medication takes a personalized medicine approach; setmelanotide is approved as a therapy for those with some of the ultra-rare genetic diseases characterized by severe, early onset obesity. This chapter reviews the currently available and anticipated medications for chronic weight management as well as those approved for the genetic and syndromic obesities.