Pancreatic lipase inhibitor
Orlistat
Brand names: Xenical, Alli
Adult dose
Dose: 120mg with each main meal containing fat (max TDS); 60mg OTC (Alli)
Route: PO
Frequency: TDS
Clinical pearls
- Adjunct to lifestyle in BMI ≥28 with risk factor or ≥30 (NICE CG189)
- Stop after 12 weeks if <5% weight loss
- Take multivitamin including fat-soluble vitamins ≥2h apart from dose
Contraindications
- Chronic malabsorption syndrome
- Cholestasis
- Pregnancy/breastfeeding
- Hypersensitivity
Side effects
- Steatorrhoea
- Faecal urgency/incontinence
- Reduced absorption of fat-soluble vitamins
- Hepatotoxicity (rare)
- Cholelithiasis
Interactions
- Ciclosporin (reduced absorption — separate by 3h)
- Levothyroxine
- Antiepileptics
- Warfarin (variable)
Monitoring
- Weight
- Renal function
- Vitamins
Reference: BNF; NICE CG189; https://bnf.nice.org.uk/drugs/orlistat/. Verify against your local formulary and the latest BNF before prescribing.
Related
Curated clinical cross-links plus same-class fallbacks.
Calculators
- SMART Risk Score for Recurrent CVD · Cardiovascular Risk
- PCSK9 Inhibitor Eligibility Assessment · Lipid Management
- Ranson Criteria (Pancreatitis) · Pancreatitis
- Pancreatic Fistula Risk Score (FRS) after Pancreatoduodenectomy · Pancreatic Surgery
- CT Severity Index (CTSI/Balthazar) for Acute Pancreatitis · Acute Pancreatitis
- Immune-Related Adverse Events (irAE) -- GI Toxicity Colitis Grading · Oncology-Related GI
Pathways
- Diabetic Ketoacidosis (DKA) · JBDS 2013 / Joint British Diabetes Societies; NICE NG17
- Adult Hypoglycaemia (Treated Diabetes) · JBDS-IP (2023): Hospital Management of Hypoglycaemia
- Adrenal Crisis · Society for Endocrinology Emergency Guidance (2024)
- Type 2 Diabetes Management · NICE NG28 2022
- Hyperthyroidism Management · BTA / ETA 2018
- Adrenal Insufficiency · Society of Endocrinology / ESE 2016