Acts in the lumen of the stomach and small intestine to form a covalent bond with the active serine residue site of gastric and pancreatic lipases. Inactivated enzymes are not available to hydrolyze dietary fat, in the form of triglycerides, into absorbable free fatty acids and monoglycerides. Effect on absorption of lipids seen as soon as 24-48 hr after dosing. Weight loss was seen within 2 weeks of starting therapy and continued for 6-12 months. Systemic absorption is not needed for activity, although a small amount is absorbed.
Metabolism occurs mainly in the GI wall.
Unabsorbed drug is excreted through the feces. To reduce risk for weight regain after prior weight loss. GI side effects may increase when taken with a high fat diet. Use with caution in those with a history of hyperoxaluria or calcium oxalate nephrolithiasis. Safety and effectiveness have not been determined in children.