Drug interactions
Hydrochlorothiazide + Olmesartan
Severity: Minor
Hydrochlorothiazide and Olmesartan: minor 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
Olmesartan tends to raise potassium while hydrochlorothiazide lowers it, so the effects partly offset. The fixed combination is widely used, but hypotension, volume depletion and renal function changes can occur.
What this interaction means in plain words
Hydrochlorothiazide and Olmesartan have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised.
Hydrochlorothiazide belongs to Cardiovascular; Olmesartan belongs to Cardiovascular.
Why it happens
Angiotensin receptor blockade reduces aldosterone-driven potassium excretion, counteracting thiazide potassium loss.
What to do
Check potassium, creatinine and blood pressure after starting or changing doses. No routine adjustment is needed if stable.
What to ask your pharmacist
- Is there anything I should notice while taking both?
- Do I need to tell my doctor at the next visit?
Pro+ members
Unlock the full page
Create an account and start a Pro+ trial to unlock the full management advice for Hydrochlorothiazide and Olmesartan, the additional notes, the evidence detail and the whole-prescription interaction checker.
- Full clinical management advice
- Additional notes
- Evidence detail
- Interaction checker for a whole prescription
Try Pro+ free for 7 days on the web. No card needed.
Other interactions of Hydrochlorothiazide
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 with Olmesartan?
MediHelp rates the interaction as minor. Hydrochlorothiazide and Olmesartan have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised. Olmesartan tends to raise potassium while hydrochlorothiazide lowers it, so the effects partly offset. The fixed combination is widely used, but hypotension, volume depletion and renal function changes can occur.
How serious is the interaction between Hydrochlorothiazide and Olmesartan?
MediHelp rates it minor, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Check potassium, creatinine and blood pressure after starting or changing doses. No routine adjustment is needed if stable.
What other medicines interact with Hydrochlorothiazide?
MediHelp also lists interactions of Hydrochlorothiazide with, for example, Dofetilide, Amifostine, Amiodarone. The full list is on the Hydrochlorothiazide page.
Full monographs, dosing and an interaction checker in the MediHelp app
Open the complete reference, check multi-drug interactions and use dosing tools in the MediHelp app.
