The failure rate of obesity treatment is very high (NH&MRC 2003) and recent research has shown that the most likely reason is the vigorous defense of body weight involving persistent changes in hunger controlling hormones and in metabolic rate. Because of these biological changes it follows that pharmacotherapy after weight loss is both logical and necessary. When pharmacotherapy is contraindicated or not effective, bariatric surgery may be necessary. What is available?
In Australia there are currently two drugs that have TGA approval for use in weight control; Phentermine (Duromine) and Orlistat (Xenical). Recently the FDA in the USA has approved a combination of phentermine and topiramate (Qnexa) and Locarserin. Under investigation are Liraglutide (Victoza); a combination of leptin and amylin and a combination of bupropion and naltraxone (Contrave). In addition there are other products in earlier stages of development. The role and scientific evidence for the effectiveness and safety of these products will be discussed.
Three bariatric procedures are performed in Australia; adjustable gastric banding, sleeve gastrectomy and Roux-en-Y bypass. Each procedure has its strengths and weaknesses. The mechanisms of action, the risks and benefits and the role of the procedures will be discussed.