What is the recommended dose for Orlistat (Xenical)?

Recommended Dosage for Orlistat

The recommended dosage of orlistat (Xenical) is one 120-mg capsule taken three times a day with each main meal containing fat. 1, 2

Dosing Details

• Prescription strength (Xenical): 120 mg capsule taken with each main meal containing fat (maximum 3 capsules daily)
• Over-the-counter strength (Alli): 60 mg capsule taken with each main meal containing fat (maximum 3 capsules daily)
• Timing: Take during or up to 1 hour after meals
• Maximum daily dose: 3 capsules (360 mg for Xenical, 180 mg for Alli)

Mechanism and Efficacy

Orlistat works by inhibiting pancreatic and gastric lipases in the gastrointestinal tract, blocking the absorption of approximately 30% of ingested dietary fat 1. This mechanism leads to:

• Weight loss of 2.78-2.81% of total body weight compared to placebo 1
• Increased likelihood of achieving 5% total body weight loss (RR 1.71) 1
• Increased likelihood of achieving 10% total body weight loss (RR 1.94) 1

Important Administration Guidelines

1. Dietary recommendations:

   • Patients should follow a reduced-calorie diet with approximately 30% of calories from fat 1
   • Distribute fat intake evenly across three main meals to minimize gastrointestinal side effects

2. Supplementation:

   • Take a multivitamin containing fat-soluble vitamins (A, D, E, and K) once daily 1
   • Take the multivitamin at bedtime or at least 2 hours before or after taking orlistat 1, 2

Common Side Effects and Management

The most common side effects are gastrointestinal and related to the medication's mechanism of action:

• Oily spotting
• Flatulence with discharge
• Fecal urgency
• Oily or fatty stools
• Increased defecation

These side effects can be minimized by:

• Strictly adhering to a low-fat diet (≤30% of calories from fat)
• Adding fiber supplements to the diet
• Distributing fat intake evenly throughout the day

Special Considerations

• Contraindications: Pregnancy, chronic malabsorption syndrome, cholestasis 1
• Drug interactions: Should not be taken with cyclosporine, L-thyroxine, warfarin, or antiepileptic drugs 1
• Monitoring: The FDA has added a label warning about potential serious liver injury 1

Duration of Treatment

Most weight loss occurs within the first 6 months of treatment 2. If a patient stops taking orlistat and begins to regain weight, restarting the medication along with diet and exercise may be considered 2.