Losartan vs Olmesartan
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Losartan (Cozaar) and olmesartan (Benicar) are both angiotensin II receptor blockers (ARBs) prescribed for hypertension. Losartan was the first ARB approved (1995), while olmesartan arrived later (2002) and is recognized as one of the more potent ARBs for blood pressure lowering.
Both drugs block the angiotensin II AT1 receptor, reducing vasoconstriction and aldosterone secretion. Despite their shared mechanism, they differ in blood pressure-lowering potency, additional pharmacological properties, and specific safety considerations.
Both are available as generics and are commonly used as alternatives to ACE inhibitors in patients who experience cough.
Losartan vs Olmesartan: Side-by-side comparison
| Category | Losartan | Olmesartan |
|---|---|---|
| Drug Class | ARB | ARB |
| Brand Name | Cozaar | Benicar |
| Usual Dose | 50-100 mg/day | 20-40 mg/day |
| BP-Lowering Potency | Moderate | High |
| Uric Acid Effect | Lowers uric acid | No effect |
| Sprue-like Enteropathy | Not reported | FDA warning (rare) |
| Generic Since | 2010 | 2016 |
Efficacy: How well does each drug work?
Olmesartan is a more potent blood pressure-lowering agent than losartan. Head-to-head studies have shown that olmesartan 20 mg produces greater systolic and diastolic blood pressure reductions than losartan 50 mg. At maximum doses, olmesartan 40 mg provides greater antihypertensive effect than losartan 100 mg.
The ROADMAP trial studied olmesartan in type 2 diabetes patients and found it delayed the onset of microalbuminuria, though the trial raised some concerns about cardiovascular events in a subgroup with pre-existing coronary disease.
Losartan has broader outcome trial evidence, including the LIFE trial (stroke reduction with left ventricular hypertrophy) and RENAAL trial (diabetic nephropathy). Losartan is also FDA-approved for diabetic nephropathy and stroke risk reduction, indications olmesartan does not have.
Side effects comparison
Both drugs are generally well tolerated with side effect rates similar to placebo. Common side effects include dizziness, headache, and upper respiratory symptoms.
Olmesartan has a unique safety concern: in 2013, the FDA issued a warning about sprue-like enteropathy — a condition characterized by severe chronic diarrhea with substantial weight loss that can develop months to years after starting olmesartan. This condition mimics celiac disease and resolves upon discontinuation. This has not been reported with losartan or other ARBs.
Both drugs share the ARB class warnings: avoid in pregnancy, risk of hyperkalemia, and caution in renal artery stenosis. Losartan uniquely lowers uric acid, which is beneficial for patients with gout.
Cost comparison
Both are available as generic medications. Losartan has been generic since 2010, and olmesartan since 2016. A 30-day supply of either costs approximately $4-$20 at most pharmacies.
Both are available in fixed-dose combinations with hydrochlorothiazide (losartan/HCTZ as Hyzaar; olmesartan/HCTZ as Benicar HCT). Olmesartan is also available in a triple combination with amlodipine and HCTZ (Tribenzor). Cost differences are minimal.
Convenience and dosing
Both are taken once daily as oral tablets. Neither requires food for absorption. Olmesartan's consistent 24-hour blood pressure control and slightly longer duration of action mean that trough blood pressure levels are well maintained.
Losartan comes in 25 mg, 50 mg, and 100 mg tablets. Olmesartan comes in 5 mg, 20 mg, and 40 mg tablets. Both allow simple dose titration.
Which is right for you?
Olmesartan may be preferred when maximum blood pressure reduction is the primary goal, as it is one of the most potent ARBs available. It is a straightforward choice for uncomplicated hypertension.
Losartan may be preferred for patients with diabetic nephropathy (FDA indication), stroke prevention with left ventricular hypertrophy (LIFE trial), or gout/hyperuricemia (uricosuric effect). It also has a longer track record and no sprue-like enteropathy concern.
Patients on olmesartan who develop unexplained chronic diarrhea and weight loss should inform their healthcare provider immediately. Consult your doctor to determine which ARB is appropriate for your situation.
Frequently asked questions
References
- [Regulatory] Cozaar (losartan potassium) prescribing information. Merck & Co. https://www.accessdata.fda.gov/drugsatfda_docs/label/2018/020386s062lbl.pdf Accessed 2026-02-28.
- [Regulatory] Benicar (olmesartan medoxomil) prescribing information. Daiichi Sankyo. https://www.accessdata.fda.gov/drugsatfda_docs/label/2013/021286s028lbl.pdf Accessed 2026-02-28.
- [Regulatory] FDA Drug Safety Communication: FDA approves label changes to include intestinal problems (sprue-like enteropathy) linked to olmesartan. July 2013. https://www.fda.gov/drugs/drug-safety-and-availability/fda-drug-safety-communication-fda-approves-label-changes-include-intestinal-problems-sprue Accessed 2026-02-28.
- [Clinical] Dahlof B, et al. Cardiovascular morbidity and mortality in the Losartan Intervention For Endpoint reduction in hypertension study (LIFE). Lancet. 2002;359(9311):995-1003. https://pubmed.ncbi.nlm.nih.gov/11937178/ Accessed 2026-02-28.
Written and fact-checked by PrescriptionDrugs.org Editorial Team
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