Drug interactions
Hydrochlorothiazide-losartan + Quinapril
Severity: Major
Hydrochlorothiazide-losartan and Quinapril: 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 an angiotensin receptor blocker with an ACE inhibitor produces dual renin-angiotensin system blockade. This raises the risk of hypotension, hyperkalemia, and acute kidney injury without clear added cardiovascular benefit in most patients.
What this interaction means in plain words
Hydrochlorothiazide-losartan and Quinapril 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.
Why it happens
Additive inhibition of the renin-angiotensin-aldosterone system at two levels.
What to do
Avoid the combination and use a single renin-angiotensin agent. If used in a specialist setting, 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?
Pro+ members
Unlock the full page
Create an account and start a Pro+ trial to unlock the full management advice for Hydrochlorothiazide-losartan and Quinapril, 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 14 days on the web. No card needed.
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
Frequently asked questions
Can I take Hydrochlorothiazide-losartan with Quinapril?
MediHelp rates the interaction as major. Hydrochlorothiazide-losartan and Quinapril 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 an angiotensin receptor blocker with an ACE inhibitor produces dual renin-angiotensin system blockade. This raises the risk of hypotension, hyperkalemia, and acute kidney injury without clear added cardiovascular benefit in most patients.
How serious is the interaction between Hydrochlorothiazide-losartan and Quinapril?
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 the combination and use a single renin-angiotensin agent. If used in a specialist setting, 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.
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.
