Recommended Dosage and Usage of Orlistat for Weight Loss
Orlistat should be taken at a dosage of 120 mg (prescription) or 60 mg (over-the-counter) three times daily with each main meal containing fat, and should be skipped if a meal contains no fat or is skipped. 1, 2
Dosage Guidelines
- Prescription strength: 120 mg capsules taken three times daily
- Over-the-counter strength: 60 mg capsules taken three times daily
- Timing: During or within 1 hour after meals containing fat 3, 1
- Maximum daily dose: Do not exceed 3 capsules daily 2
Patient Selection Criteria
Orlistat is indicated for:
- Adults aged 18 years and older 1, 2
- BMI ≥30 kg/m² (obese) or
- BMI ≥28 kg/m² (overweight) with weight-related comorbidities 1
The FDA label provides a height/weight chart to help determine if orlistat is appropriate based on the patient's measurements 2.
Administration Guidelines
- Must be used in conjunction with a reduced-calorie, low-fat diet (≤30% of calories from fat) 3, 1
- Skip the dose if a meal contains no fat or is skipped 1
- Take a daily multivitamin containing fat-soluble vitamins (A, D, E, K) at bedtime or at least 2 hours apart from orlistat to prevent vitamin deficiencies 3, 1
- Lipophilic medications should be taken at least 2 hours before or after orlistat 1
Efficacy Expectations
- Most weight loss occurs in the first 6 months of treatment 1, 2
- Clinical trials showed weight loss of 2.81 kg more than placebo 1
- Approximately 53% of patients achieve 5% total body weight loss 1
- If 5% weight loss is not achieved after 12 weeks, consider discontinuing orlistat 1
Side Effect Management
- Gastrointestinal side effects occur in 70-80% of users, including oily spotting, fecal urgency, flatulence with discharge, and fecal incontinence 1
- These side effects typically occur early in treatment (within first 4 weeks) and often resolve despite continued treatment 1
- Adding fiber supplements can help manage gastrointestinal symptoms 1
- Approximately 4% of patients discontinue orlistat due to GI complaints 1
Important Monitoring
- Regular assessment of gastrointestinal symptoms
- Periodic liver function monitoring (FDA has added a label warning about potential serious liver injury) 1
- Evaluation of fat-soluble vitamin levels for extended treatment 1
- Monitoring of medication levels for patients on concurrent lipophilic drugs 1
Contraindications
Orlistat should not be used in:
- Pregnancy or breastfeeding
- Chronic malabsorption syndrome
- Cholestasis
- Patients with cholelithiasis (gallstones)
- Concurrent use of cyclosporine, warfarin, or antiepileptic drugs 1
Clinical Considerations
The American Gastroenterological Association suggests against routine use of orlistat due to modest weight loss benefits and significant gastrointestinal side effects 3, 1. However, patients who place high value on potential small weight loss and low value on GI adverse effects may reasonably choose treatment with orlistat 3.
If weight regain occurs after stopping orlistat, consider restarting the medication along with diet and exercise program 2.