5. XENICAL: Indications for Use
XENICAL is indicated for obesity management, including weight loss and weight maintenance, when used in conjunction with a reduced-calorie diet, and for reduction of the risk of weight regain after prior weight loss. Organic causes of obesity, such as hypothyroidism, should be excluded before prescribing XENICAL. XENICAL is not recommended for use during pregnancy or lactation.
6. Orlistat: Mechanism of Action
Orlistat is a non-systemically acting drug that works locally to inhibit GI lipases and block or prevent the absorption of about 30% of dietary fat. Triglycerides are the major fat in food. They are composed of three fatty acid tails, with a glycerol backbone. In this form they cannot be absorbed. Pancreatic and gastric lipases are the primary enzymes involved in the metabolism and absorption of dietary fat. In the small intestine, lipases cleave the triglyceride molecule, splitting off the fatty acid tails from the glycerol backbone. Orlistat binds to lipase, preventing it from breaking down triglycerides. The broken-down components of the triglycerides are then absorbed. The intact triglycerides cannot be absorbed and are subsequently excreted in the feces. Orlistat has been shown to prevent the absorption of about 30% of dietary fat.
