Xenical (orlistat) is a prescription medication specifically designed to support weight management in adults when used alongside a reduced-calorie diet. As a lipase inhibitor, it operates within the gastrointestinal tract to prevent the absorption of approximately one-third of dietary fat intake. This targeted mechanism of action makes it a valuable tool in comprehensive weight loss strategies for individuals with obesity or overweight conditions accompanied by related risk factors. Its efficacy is well-documented in clinical studies, providing a pharmacologic option that complements lifestyle modifications.

Features

• Active ingredient: Orlistat 120 mg
• Pharmaceutical class: Lipase inhibitor
• Administration: Oral capsule
• Prevents absorption of dietary fats by inhibiting gastrointestinal lipases
• Non-systemic mode of action; works locally in the gut
• Requires concomitant reduced-calorie diet

Benefits

• Supports clinically significant weight loss when combined with diet and exercise
• Reduces absorption of dietary fats by approximately 30%
• Helps improve weight-related parameters such as BMI and waist circumference
• May contribute to improved metabolic markers in overweight patients
• Provides a non-stimulant approach to weight management
• Can be integrated into long-term weight maintenance strategies

Common use

Xenical is indicated for obesity management in adults with a body mass index (BMI) ≥30 kg/m², or ≥27 kg/m² in the presence of other risk factors such as hypertension, type 2 diabetes, or dyslipidemia. It is used as an adjunct to a medically supervised reduced-calorie diet and should be incorporated into a comprehensive weight management program that includes behavioral modification and physical activity. Treatment is typically recommended for patients who have not achieved adequate weight loss through diet and exercise alone.

Dosage and direction

The recommended dosage is one 120 mg capsule taken three times daily with each main meal containing fat. The capsule should be taken during the meal or up to one hour after eating. If a meal is missed or contains no fat, the dose of Xenical should be omitted. The medication works by blocking fat absorption from the meals with which it is taken, making timing relative to fat-containing meals essential for optimal efficacy. Dosage adjustment is not typically required for elderly patients or those with renal or hepatic impairment.

Precautions

Patients should be advised to follow a nutritionally balanced, reduced-calorie diet that derives approximately 30% of calories from fat. Distribution of daily fat intake over three main meals is recommended. A multivitamin supplement containing fat-soluble vitamins (A, D, E, and K) should be taken once daily at least 2 hours before or after Xenical administration. Use with caution in patients with history of hyperoxaluria or calcium oxalate nephrolithiasis. Monitor patients for any signs of liver injury, although such events are rare.

Contraindications

Xenical is contraindicated in patients with chronic malabsorption syndrome or cholestasis. It should not be used during pregnancy or by nursing mothers. Hypersensitivity to orlistat or any component of the formulation prohibits use. The medication is not recommended for use in children or adolescents under 18 years of age. Patients with anorexia nervosa or bulimia should not use this medication.

Possible side effects

The most common side effects are gastrointestinal in nature and result from the pharmacologic action of preventing fat absorption:

• Oily spotting
• Flatus with discharge
• Fecal urgency
• Fatty/oily stool
• Oily evacuation
• Increased defecation
• Fecal incontinence

These effects are generally mild to moderate, decrease with continued use, and are often managed through dietary fat reduction. Less common side effects may include tooth/gum disorders, headache, upper respiratory infection, and back pain. Rare cases of severe liver injury have been reported.

Drug interaction

Xenical may reduce absorption of fat-soluble vitamins and certain medications. Specifically monitor:

• Cyclosporine (administer at least 2 hours before or after Xenical)
• Warfarin (monitor INR closely)
• Levothyroxine (separate administration by at least 4 hours)
• Antiepileptic medications (monitor seizure control)
• Amiodarone
• Oral contraceptives (recommend additional contraceptive method)

Patients taking these medications concurrently require careful monitoring and possible dosage adjustments.

Missed dose

If a dose is missed, it should be skipped and the regular dosing schedule resumed with the next meal. Do not double the dose to make up for a missed capsule. The medication is only effective when taken with fat-containing meals, so taking it without dietary fat provides no benefit while potentially increasing side effects.

Overdose

Cases of overdose have reported with doses up to 400 mg three times daily. The most likely manifestations are gastrointestinal events similar to the known side effects but potentially more severe. There is no specific antidote for orlistat overdose. Treatment should be symptomatic and supportive. Medical attention should be sought if concerning symptoms develop or if very large quantities have been ingested.

Storage

Store at room temperature between 15-30°C (59-86°F). Keep in original container with desiccant, tightly closed. Protect from moisture and light. Do not use if the seal is broken or missing. Keep out of reach of children and pets. Do not use after the expiration date printed on the packaging.

Disclaimer

This information is provided for educational purposes only and does not replace professional medical advice. Xenical is a prescription medication that should only be used under appropriate medical supervision. Individual results may vary. Patients should consult with their healthcare provider before starting or changing any treatment regimen. The full prescribing information should be reviewed before initiation of therapy.

Reviews

Clinical trials demonstrate that Xenical, when combined with lifestyle modification, produces significantly greater weight loss than placebo alone. In year-long studies, approximately 40% of patients achieved ≥5% weight loss, with about 20% achieving ≥10% weight loss. Many patients report satisfactory results when adhering to dietary recommendations, though gastrointestinal side effects are commonly noted during the initial treatment period. Long-term studies support its efficacy in weight maintenance when used as part of a comprehensive management approach.