Mechanisms of action and clinical applications of anti-obesity drugs currently available in Korea

ABSTRACT

Over the last 5 years, the Korean Ministry of Food and Drug Safety has approved four anti-obesity drugs for long-term weight management. In this review, the mechanisms of action and clinical applications of lorcaserin, naltrexone/bupropion, liraglutide, and phentermine/topiramate have been clarified. Lorcaserin stimulates proopiomelanocortin/cocaine- and amphetamine-regulated transcript neurons in the arcuate nucleus. Naltrexone/bupropion reduces body weight by controlling the hedonic reward system of food intake. The hypophagic effect of liraglutide depends on the direct activation of the proopiomelanocortin/cocaine- and amphetamine-regulated transcript neurons and indirect suppression of neuropeptide Y/agouti-related peptide neurons through gammaaminobutyric acid-dependent signaling, with an additional thermogenic effect. Phentermine/topiramate induces weight loss by elevating the norepinephrine levels in the hypothalamus, reducing energy deposition in the adipose tissue and skeletal muscle, and elevating the corticotropin-releasing hormone in the hypothalamus. In patients with high cardiovascular risks or type 2 diabetes mellitus, lorcaserin and liraglutide are appropriate. In patients with mood disorders, naltrexone/bupropion could be considered as the first choice of therapy. Notably, lorcaserin and liraglutide are neutral in the aspect of sleep disorder. In case of obese individuals with obstructive sleep apnea, liraglutide or phentermine/topiramate would be selected as the treatment option. These four drugs should be used after considering the patients' co-morbidities of obesity.