Orlistat (Xenical) is a gastrointestinal lipase inhibitor used for obesity management and must be used in combination with a low-calorie diet. It works by inhibiting the absorption of dietary fats, but strict adherence to medication guidelines is required to avoid adverse reactions.
Orlistat (Xenical) Medication Precautions
Target Population and Contraindications
Target Population: Patients with simple obesity who have a BMI ≥ 30 kg/m², or patients with a BMI ≥ 27 kg/m² accompanied by risk factors such as hypertension and diabetes.
Absolute Contraindications: Pregnant women (may cause fetal developmental abnormalities), patients with chronic malabsorption syndrome, cholestasis, and those allergic to orlistat.
Dosage and Administration
Standard Dosage: 120 mg each time, three times a day, taken with main meals or within 1 hour after meals. The dose can be omitted if there is no fat in the meal.
Dietary Requirements: Daily fat intake should not exceed 30% of total calories (e.g., ≤ 50 grams of fat in a 1,500-calorie daily diet), and it should be evenly distributed among three meals. A high-fat diet may worsen gastrointestinal adverse reactions.
Drug Interactions
Cyclosporine: The two medications must be taken with an interval of at least 3 hours to avoid a decrease in cyclosporine blood concentration.
Levothyroxine: Administer the two medications with an interval of more than 4 hours, and monitor thyroid function.
Warfarin: May reduce vitamin K absorption; closely monitor coagulation parameters.
Antiepileptic drugs/anti-HIV drugs: May reduce efficacy; dosage adjustment or medication replacement is required.
Nutritional Supplementation
Mandatory Supplementation: Take a daily multivitamin containing fat-soluble vitamins (A, D, E, K, and beta-carotene), with an interval of 2 hours from orlistat (e.g., taken before bedtime).
Orlistat (Xenical) Medication Monitoring
Adverse Reaction Monitoring
Common Gastrointestinal Reactions: Oily spots, oily discharge during flatulence, urgency to defecate, etc. These usually diminish with continued medication use. Seek medical attention if symptoms are severe or persist for more than 4 weeks.
Rare Severe Reactions
Liver Injury: Discontinue use immediately and check liver function if symptoms such as loss of appetite, jaundice, or right upper abdominal pain occur.
Kidney Stones/Kidney Disease: Monitor urinary oxalate levels, especially in patients with a history of renal insufficiency.
Cholecystitis: Rapid weight loss may induce gallstones; pay attention to symptoms of right upper abdominal pain.
Metabolic Index Monitoring
Vitamin Levels: For patients on long-term medication, test fat-soluble vitamin concentrations every 6-12 months to prevent deficiencies.
Blood Glucose and Lipids: Adjust the dosage of hypoglycemic drugs for diabetic patients; regularly recheck cholesterol and triglycerides.
Special Population Monitoring
Elderly Patients: Renal function may decline; assess medication tolerance.
Adolescent Patients: Behavioral intervention is required; regularly measure BMI and growth and development indicators.


