Angiotensin Receptor Blocker (ARB)
Pregnancy: Contraindicated
Losartan
Brand names: Cozaar
Adult dose
Dose: 25–100 mg
Route: Oral
Frequency: Once daily
Max: 100 mg/day
Start 25–50 mg; usual maintenance 50–100 mg. Used for hypertension, type 2 diabetic nephropathy, heart failure (if ACE-inhibitor intolerant). Also has uricosuric effect — useful in gout patients with hypertension.
Paediatric dose
Dose: 0.7 mg/kg
Route: Oral
Frequency: Once daily
Max: 50 mg/day
For children ≥6 years (hypertension): 0.7 mg/kg once daily up to 50 mg/day under specialist guidance.
Dose adjustments
Renal
No initial dose adjustment, but use with caution; avoid if eGFR <30 or in bilateral renal artery stenosis.
Hepatic
Reduce dose in hepatic impairment — start 25 mg.
Paediatric weight-based calculator
For children ≥6 years (hypertension): 0.7 mg/kg once daily up to 50 mg/day under specialist guidance.
Clinical pearls
- Unlike ACE inhibitors, does NOT cause cough — preferred alternative for ACE-inhibitor–intolerant patients
- Unique uricosuric property makes it useful in hypertensive patients with gout
- LIFE trial: losartan superior to atenolol in reducing CV events in hypertensive LVH patients
Contraindications
- Pregnancy
- Bilateral renal artery stenosis
- Concomitant aliskiren in diabetes/renal impairment
Side effects
- Dizziness
- Hypotension
- Hyperkalaemia
- AKI
- Less cough than ACE inhibitors (no bradykinin accumulation)
Interactions
- NSAIDs (reduce efficacy)
- Potassium-sparing diuretics (hyperkalaemia)
- Lithium (increased levels)
- Fluconazole (inhibits CYP2C9 — increases losartan active metabolite E-3174)
Monitoring
- U&E at baseline and after initiation/dose change
- Blood pressure
Reference: BNFc; BNF 90; NICE NG136; LIFE Trial (Lancet 2002); BNFc. Verify against your local formulary and the latest BNF before prescribing.
Related
Curated clinical cross-links plus same-class fallbacks.
Calculators