Technical Information

This section is dedicated to technical information about Xenical. It details the class of drug that Xenical is, and details both how and why it works.

The active ingredient in Xenical is orlistat, which is a gastrointestinal lipase inhibitor.

It acts directly in the gastrointestinal tract to prevent the digestive lipases digesting fat. This prevents about 30% of fat in the diet from being absorbed. It has no effect on any other digestive enzymes in the gastrointestinal tract, and the absorption of carbohydrates and proteins is not affected. However, Xenical reduces the absorption of certain fat soluble vitamins (vitamins A, D and E) and also beta-carotene, so patients should be counselled to take a multivitamin that contains these fat-soluble vitamins to ensure adequate nutrition. The multivitamin should be taken two or more hours before or after taking Xenical to ensure that it is properly absorbed. Taking the multivitamin before going to bed is appropriate.

Xenical can improve cardio vascular risk factors by reducing LDL cholesterol levels and can improve glycemic control in patients with type II diabetes.