Drug interactions
Captopril-hydrochlorothiazide + Metolazone
Severity: Major
Captopril-hydrochlorothiazide and Metolazone: 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
Metolazone combined with hydrochlorothiazide produces profound sequential nephron blockade, causing marked diuresis, hypokalemia, hyponatremia and volume depletion. With captopril this raises the risk of hypotension and acute kidney injury.
What this interaction means in plain words
Captopril-hydrochlorothiazide and Metolazone 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.
Captopril-hydrochlorothiazide belongs to Cardiovascular; Metolazone belongs to Cardiovascular.
Why it happens
Duplicate thiazide-type diuretic action with additive electrolyte loss and volume depletion, compounded by ACE inhibitor reduction of glomerular filtration pressure.
What to do
Avoid combining two thiazide-type diuretics unless deliberately intended for resistant edema. If used, monitor electrolytes, renal function, weight 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 Captopril-hydrochlorothiazide
- Aliskiren + Captopril-hydrochlorothiazide Contraindicated
- Captopril-hydrochlorothiazide + Dofetilide Contraindicated
- Captopril-hydrochlorothiazide + Sacubitril / valsartan Contraindicated
- Aceclofenac + Captopril-hydrochlorothiazide Major
- Aldesleukin + Captopril-hydrochlorothiazide Major
- Amifostine + Captopril-hydrochlorothiazide Major
Other interactions of Metolazone
Frequently asked questions
Can I take Captopril-hydrochlorothiazide with Metolazone?
MediHelp rates the interaction as major. Captopril-hydrochlorothiazide and Metolazone 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. Metolazone combined with hydrochlorothiazide produces profound sequential nephron blockade, causing marked diuresis, hypokalemia, hyponatremia and volume depletion. With captopril this raises the risk of hypotension and acute kidney injury.
How serious is the interaction between Captopril-hydrochlorothiazide and Metolazone?
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 thiazide-type diuretics unless deliberately intended for resistant edema. If used, monitor electrolytes, renal function, weight and blood pressure closely.
What other medicines interact with Captopril-hydrochlorothiazide?
MediHelp also lists interactions of Captopril-hydrochlorothiazide with, for example, Aliskiren, Dofetilide, Sacubitril / valsartan. The full list is on the Captopril-hydrochlorothiazide page.
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