Drug interactions
Hydrochlorothiazide-losartan + Olmesartan
Severity: Major
Hydrochlorothiazide-losartan and Olmesartan: 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 provides dual renin-angiotensin system blockade, which increases the risk of hypotension, hyperkalemia and renal impairment without added cardiovascular benefit. The combination is generally discouraged.
What this interaction means in plain words
Hydrochlorothiazide-losartan and Olmesartan 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-losartan belongs to Cardiovascular; Olmesartan belongs to Cardiovascular.
Why it happens
Additive blockade of the angiotensin II type 1 receptor and aldosterone effects, leading to potassium retention and reduced glomerular filtration.
What to do
Avoid combining two ARBs; use a single ARB titrated to 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-losartan
- Aliskiren + Hydrochlorothiazide-losartan Contraindicated
- Dofetilide + Hydrochlorothiazide-losartan Contraindicated
- Hydrochlorothiazide-losartan + Sparsentan Contraindicated
- Aceclofenac + Hydrochlorothiazide-losartan Major
- Aldesleukin + Hydrochlorothiazide-losartan Major
- Amifostine + Hydrochlorothiazide-losartan Major
Other interactions of Olmesartan
- Aliskiren + Olmesartan Contraindicated
- Olmesartan + Sparsentan Contraindicated
- Aldesleukin + Olmesartan Major
- Amifostine + Olmesartan Major
- Amiloride + Olmesartan Major
- Amlodipine-benazepril + Olmesartan Major
Frequently asked questions
Can I take Hydrochlorothiazide-losartan with Olmesartan?
MediHelp rates the interaction as major. Hydrochlorothiazide-losartan and Olmesartan 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 provides dual renin-angiotensin system blockade, which increases the risk of hypotension, hyperkalemia and renal impairment without added cardiovascular benefit. The combination is generally discouraged.
How serious is the interaction between Hydrochlorothiazide-losartan and Olmesartan?
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 combining two ARBs; use a single ARB titrated to dose. If unavoidable, monitor potassium, creatinine and blood pressure closely.
What other medicines interact with Hydrochlorothiazide-losartan?
MediHelp also lists interactions of Hydrochlorothiazide-losartan with, for example, Aliskiren, Dofetilide, Sparsentan. The full list is on the Hydrochlorothiazide-losartan page.
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