Drug interactions
Hydrochlorothiazide-olmesartan + Losartan
Severity: Major
Hydrochlorothiazide-olmesartan and Losartan: major interaction.
Last updated
For healthcare professionals — reference only. This page is a brief summary, not medical advice and not a substitute for official labeling or clinical judgement. Always verify before prescribing or dispensing.
Summary
Combining two angiotensin receptor blockers gives dual blockade of the renin-angiotensin system without added benefit. It increases the risk of hypotension, hyperkalemia and renal dysfunction, and hydrochlorothiazide adds volume depletion risk.
What this interaction means in plain words
Hydrochlorothiazide-olmesartan and Losartan can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for.
Hydrochlorothiazide-olmesartan belongs to Cardiovascular; Losartan belongs to Cardiovascular.
Why it happens
Additive angiotensin II receptor blockade reduces aldosterone and glomerular filtration pressure, causing potassium retention and renal impairment.
What to do
Avoid using two ARBs together and use one agent at an optimized dose. If unavoidable, monitor potassium, creatinine and blood pressure closely.
What to ask your pharmacist
- Does the benefit of taking both outweigh the risk in my case?
- Do I need any blood test, ECG or other check while on both?
- What early warning signs should I watch for, and what should I do if they appear?
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Other interactions of Hydrochlorothiazide-olmesartan
- Aliskiren + Hydrochlorothiazide-olmesartan Contraindicated
- Dofetilide + Hydrochlorothiazide-olmesartan Contraindicated
- Hydrochlorothiazide-olmesartan + Sparsentan Contraindicated
- Acemetacin + Hydrochlorothiazide-olmesartan Major
- Amifostine + Hydrochlorothiazide-olmesartan Major
- Amiloride + Hydrochlorothiazide-olmesartan Major
Other interactions of Losartan
- Aliskiren + Losartan Contraindicated
- Losartan + Sparsentan Contraindicated
- Amifostine + Losartan Major
- Amiloride + Losartan Major
- Amlodipine-benazepril + Losartan Major
- Amlodipine-hydrochlorothiazide-valsartan + Losartan Major
Frequently asked questions
Can I take Hydrochlorothiazide-olmesartan with Losartan?
MediHelp rates the interaction as major. Hydrochlorothiazide-olmesartan and Losartan can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for. Combining two angiotensin receptor blockers gives dual blockade of the renin-angiotensin system without added benefit. It increases the risk of hypotension, hyperkalemia and renal dysfunction, and hydrochlorothiazide adds volume depletion risk.
How serious is the interaction between Hydrochlorothiazide-olmesartan and Losartan?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid using two ARBs together and use one agent at an optimized dose. If unavoidable, monitor potassium, creatinine and blood pressure closely.
What other medicines interact with Hydrochlorothiazide-olmesartan?
MediHelp also lists interactions of Hydrochlorothiazide-olmesartan with, for example, Aliskiren, Dofetilide, Sparsentan. The full list is on the Hydrochlorothiazide-olmesartan page.
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