Description

Orlistat is a lipase inhibitor medication used to treat obesity. It is designed to be used in conjunction with a reduced-calorie, low-fat diet and exercise. Unlike many weight-loss medications that act on the central nervous system, Orlistat works locally in the digestive system to prevent the absorption of dietary fat.

Indication

Orlistat is indicated for weight management, including weight loss and weight maintenance, in overweight and obese adults (those with a BMI of 27 kg/m² or greater with other risk factors or 30 kg/m² or greater). It is intended for long-term use and is most effective when combined with lifestyle changes.

Mechanism of Action

Orlistat works by irreversibly inhibiting gastrointestinal lipases, which are enzymes produced in the stomach and pancreas. These enzymes are responsible for breaking down dietary triglycerides (fat) into smaller, absorbable free fatty acids and monoglycerides.

By blocking the action of these lipases, Orlistat prevents the digestion of a significant portion of dietary fat (approximately 30%). The undigested fat is then eliminated from the body through bowel movements. This reduction in calorie absorption from fat helps to create a negative energy balance, which ultimately leads to weight loss. The medication does not affect appetite or metabolism.