Drug interactions
Hydrochlorothiazide-losartan + Spironolactone
Severity: Major
Hydrochlorothiazide-losartan and Spironolactone: 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
Spironolactone and losartan both promote potassium retention, which can lead to clinically significant hyperkalemia, particularly in renal impairment, heart failure or diabetes. The hydrochlorothiazide component lowers potassium but does not reliably prevent this.
What this interaction means in plain words
Hydrochlorothiazide-losartan and Spironolactone 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; Spironolactone belongs to Cardiovascular.
Why it happens
Aldosterone antagonism and angiotensin receptor blockade additively reduce renal potassium excretion.
What to do
Monitor serum potassium and renal function at baseline, within one week, and regularly thereafter. Reduce or stop spironolactone and avoid potassium supplements if potassium rises.
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 Spironolactone
- Amiloride + Spironolactone Contraindicated
- Eplerenone + Spironolactone Contraindicated
- Spironolactone + Triamterene Contraindicated
- Abiraterone + Spironolactone Major
- Aceclofenac + Spironolactone Major
- Acemetacin + Spironolactone Major
Frequently asked questions
Can I take Hydrochlorothiazide-losartan with Spironolactone?
MediHelp rates the interaction as major. Hydrochlorothiazide-losartan and Spironolactone 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. Spironolactone and losartan both promote potassium retention, which can lead to clinically significant hyperkalemia, particularly in renal impairment, heart failure or diabetes. The hydrochlorothiazide component lowers potassium but does not reliably prevent this.
How serious is the interaction between Hydrochlorothiazide-losartan and Spironolactone?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor serum potassium and renal function at baseline, within one week, and regularly thereafter. Reduce or stop spironolactone and avoid potassium supplements if potassium rises.
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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