Drug interactions
Hydrochlorothiazide-losartan + Metolazone
Severity: Major
Hydrochlorothiazide-losartan 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 a strong sequential nephron blockade, with marked diuresis. This can cause severe hypokalemia, hyponatremia, volume depletion, hypotension and renal impairment.
What this interaction means in plain words
Hydrochlorothiazide-losartan 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.
Hydrochlorothiazide-losartan belongs to Cardiovascular; Metolazone belongs to Cardiovascular.
Why it happens
Additive inhibition of sodium chloride reabsorption in the distal tubule by two thiazide-type diuretics.
What to do
Avoid routine duplication of thiazide-type diuretics. If both are required, 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 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 Metolazone
Frequently asked questions
Can I take Hydrochlorothiazide-losartan with Metolazone?
MediHelp rates the interaction as major. Hydrochlorothiazide-losartan 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 a strong sequential nephron blockade, with marked diuresis. This can cause severe hypokalemia, hyponatremia, volume depletion, hypotension and renal impairment.
How serious is the interaction between Hydrochlorothiazide-losartan 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 routine duplication of thiazide-type diuretics. If both are required, monitor electrolytes, renal function, weight 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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