Generic
Orlistat
14 brands available in the market
At a glance
Orlistat is a lipase inhibitor used for obesity. It blocks absorption of dietary fat from the stomach and small intestine to help with weight loss. It does not suppress appetite but limits fat absorption from food.
Description
Orlistat is a potent, specific and long-acting lipase inhibitor. It forms a covalent bond with the active serine site of gastric and pancreatic lipases in the lumen of the stomach and upper small intestine, inactivating the enzyme. The inactivated enzyme cannot hydrolyze dietary triglycerides into absorbable free fatty acids and monoglycerides, creating a caloric deficit which has a positive effect on weight control.
Indications
- Obesity (BMI >30 kg/m²)
- Overweight (BMI >28 kg/m²) with associated risk factors (type 2 diabetes, hyperlipidemia, hypertension)
Therapeutic class
Appetite Suppressant Drugs/Anti-obesity Drugs
Pharmacological class
Lipase Inhibitor
Pharmacology
Orlistat binds to gastric and pancreatic lipases to inactivate them, preventing hydrolysis of dietary triglycerides into absorbable fatty acids and monoglycerides. Undigested triglycerides are excreted in feces, creating a caloric deficit for weight loss.
Mechanism of action
Helps with weight loss by blocking dietary fat absorption.
Dosage
Adult Dose (Oral):
- BMI >30 kg/m² or BMI >27 kg/m² with risk factors: 120 mg three times daily with each main meal
- BMI >28 kg/m² (regardless of risk factors): 60 mg three times daily
- Omit dose if meal is missed or contains no fat
- Discontinue if unable to lose 5% body weight in first 12 weeks
Pediatric Dose: Safety and efficacy not established in children <12 years
Administration
- Take immediately before, during or up to 1 hour after each main meal
- Swallow capsule whole; do not chew, crush or break
- Fatty meals may increase gastrointestinal side effects
Missed dose
If you miss a dose, take it as soon as you remember; skip if it's almost time for next dose; do not double the dose.
Side effects
Common Side Effects:
- Abdominal pain
- Fat in stool
- Flatus with discharge
- Oily spotting
- Diarrhea
- Abdominal cramp
- Flatulence
- Soft stools
Rare: Influenza, anxiety, headache, fatigue, hypersensitivity reactions (pruritus, exanthema, urticaria, angioedema, anaphylaxis)
Precautions & warnings
- Exclude organic causes of obesity (e.g., hypothyroidism) before starting
- Take fat-soluble vitamin (A, D, E, K) supplements
- Diabetic patients may need antidiabetic dose adjustment
- Separate cyclosporine by at least 2 hours
- Separate levothyroxine by at least 4 hours
- Monitor INR in warfarin patients
Contraindications
- Chronic malabsorption syndrome
- Cholestasis
- Hypersensitivity
- Pregnancy
- Lactation
Drug interactions
- May decrease absorption of fat-soluble vitamins, amiodarone, propafenone
- May decrease plasma levels of ciclosporin
- May alter effects of warfarin (monitor INR)
- May elevate plasma levels of pravastatin
Food interactions
No harmful interaction with alcohol.
Use in pregnancy
Use in Pregnancy: Orlistat is highly unsafe during pregnancy (Category X); definite evidence of severe fetal harm. Completely contraindicated.
Pregnancy Category: X — always consult a doctor before taking during pregnancy.
Use in lactation
Use in Lactation: Orlistat is safe during breastfeeding; not significantly excreted in breast milk.
Pediatric use
Safety and efficacy not established in children under 12 years.
Geriatric use
Safety and efficacy not studied in elderly patients.
Renal / hepatic impairment
Renal Impairment: Safe in kidney disease; dose adjustment may not be needed (may be associated with kidney stone formation).
Hepatic Impairment: Safe in liver disease; dose adjustment may not be needed.
Overdose effects
Overdose: Systemic effects rapidly reversible; observe for 24 hours.
Storage conditions
Store in a cool and dry place below 30°C, protect from light & moisture; keep out of reach of children.
Chemical structure
Orlistat