Indications

Orlistat is indicated for obesity management including weight loss and weight maintenance when used in conjunction with a reduced-calorie diet. Orlistat is also indicated for the reduction of the risk of weight regain after prior weight loss. Orlistat 120 mg is indicated for obese patients with an initial body mass index (BMI) ≥30 kg/m2 or ≥27 kg/m2 in the presence of other risk factors (eg, hypertension, diabetes, dyslipidemia) and Orlistat 60 mg is indicated for overweight & obese patients with an initial body mass index (BMI) ≥25 kg/m2.

Therapeutic Class

Appetite suppressant drugs/Anti-obesity drugs

Pharmacology

Orlistat is a reversible inhibitor of gastrointestinal lipase. It exerts its therapeutic activity in the lumen of the stomach and small intestine by forming a covalent bond with the active serine residue site of gastric and pancreatic lipase. The inactivated enzymes are thus unavailable to hydrolyze dietary fat in the form of triglycerides into absorbable free fatty acids and monoglycerides. As undigested triglycerides are not absorbed, the resulting caloric deficit may have a positive effect on weight control.

Dosage & Administration

The recommended dose of Orlistat is one 60 mg or 120 mg capsule three times a day with each main meal containing fat (during or up to 1 hour after the meal). The patient should be on a nutritionally balanced, reduced-calorie diet that contains approximately 30% of calories from fat. The daily intake of fat, carbohydrate, and protein should be distributed over three main meals. If a meal is occasionally missed or contains no fat, the dose of Orlistat can be omitted.

Because Orlistat has been shown to reduce the absorption of some fat-soluble vitamins and beta-carotene, patients should be counseled to take a multivitamin containing fat-soluble vitamin to ensure adequate nutrition. The vitamin supplement should be taken at least 2 hours before or after the administration of Orlistat, such as at bedtime.

Interaction

May reduce the absorption of iodine salts and/or levothyroxine, fat-soluble vit (A, D, E, K) and beta carotene. May decrease plasma levels of ciclosporin and amiodarone. May decrease the efficacy of antiepileptic drugs (e.g. valproate, lamotrigine), antiretrovirals, antidepressants, antipsychotics (including lithium). Additive effect on glycaemic control with antidiabetics. May cause hormonal contraceptive failure. May enhance the anticoagulant effect of warfarin.

Contraindications

Orlistat is contraindicated in Pregnancy, Patients with chronic malabsorption syndrome, Patients with cholestasis, Patients with known hypersensitivity to Orlistat or to any component of this product.

Side Effects

Commonly-observed adverse events associated with the use of Orlistat include oily spotting, flatus with discharge, fecal urgency, fatty/oily stool, oily evacuation, increased defecation, fecal incontinence.

Pregnancy & Lactation

Pregnancy Category X. Orlistat is contraindicated during pregnancy, because weight loss offers no potential benefit to a pregnant woman and may result in fetal harm.

It is not known whether Orlistat is present in human milk or not. Caution should be exercised when Orlistat is administered to a nursing woman.

Precautions & Warnings

Patients should be advised to adhere to dietary guidelines. gastrointestinal events may increase when orlistat is taken with a diet high in fat (>30% of calories from fat). The daily intake of fat should be distributed over three main meals. If a meal is missed, the dose of orlistat may be omitted.

Use in Special Populations

Pediatric use: Safety and effectiveness in pediatric patients below the age of 12 have not been established.

Overdose Effects

Single doses of 800 mg and multiple doses of up to 400 mg three times a day for 15 days have been studied in normal weight and obese subjects without significant adverse findings. If a significant overdose of orlistat occur, it is recommended that the patient be observed for 24 hours. Based on human and animal studies, any systemic effects attributable to the lipase inhibiting properties of orlistat should be rapidly reversible

Storage Conditions

Store below 25°C; excursions permitted to 15° to 30°C. Keep the medicine out of reach of children.