Pharmacotherapy for weight loss

A severely obese 28 year old woman (body mass index (BMI) 37.9) with type 2 diabetes, controlled hypertension, and sleep apnoea is seeking your advice about weight loss. She has lost 6 kg over the past year by reducing portion sizes, but her weight has recently plateaued. She does not want to consider bariatric surgery and asks instead about drug treatments. Current treatment for obesity consists primarily of health behaviour modification (diet, exercise, and behavioural therapy) for all patients and bariatric surgery for a minority of selected severely obese people.1 Because health behaviour modification is unsuccessful in many patients, and the availability of bariatric surgery is limited, additional adjunctive, effective, and safe obesity treatments are needed. To date, antiobesity drugs have not adequately filled this therapeutic void. The serotonergic agents fenfluramine and dexfenfluramine were withdrawn in 1997 because of associations with cardiac valvulopathy and pulmonary hypertension.2 After the withdrawals of rimonabant ( Acomplia ) in 2009 for depression and suicidal ideation, and sibutramine ( Meridia, Reductil ) in 2010 because of increased cardiovascular risk, orlistat became the only agent available for long term weight management. In 2012, two new oral agents—phentermine and extended release (ER) topiramate ( Qsymia ) and lorcaserin ( Belviq )—were approved by the US Food and Drug Administration as adjuvants to health behaviour modification in patients with a BMI of greater than 30 or greater than 27 if they also had an obesity related comorbidity, such as hypertension, dyslipidaemia, or type 2 diabetes. As discussed elsewhere, the European Medicines Agency did not approve either agent, citing toxicity concerns and a lack of morbidity and mortality data.3 Here, we provide a clinically focused summary to guide GPs in the use of these drugs. ### Orlistat This inhibitor of gastric and pancreatic lipase prevents intestinal fat metabolism and absorption.4 Prescription orlistat ( Xenical ) has been …