Overall, all of the included studies that assessed the clinical effectiveness of either orlistat or sibutramine demonstrated that both drugs were capable of promoting weight loss. These two studies concluded that sibutramine was more effective than orlistat. With respect to adverse events, reporting was inconsistent throughout studies, but typically orlistat was associated with gastrointestinal disturbances and several reports suggested that sibutramine might increase blood pressure and heart rate. Indeed adverse reactions have been reported to Health Canada in patients with a history of cardiovascular disease, those with unstable or uncontrolled hypertension, and other contraindicated conditions. Two studies reported that treatment with either orlistat or sibutramine was not cost-effective when compared with diet or lifestyle modifications alone. The six remaining studies all reported that orlistat and sibutramine were cost-effective; however, the HTA was the only study that suggested that sibutramine was more cost-effective than orlistat (the other studies either evaluated only one drug or deemed the two drugs to be equivalent in cost-effectiveness).
