Drug interactions
Fosinopril-hydrochlorothiazide + Metolazone
Severity: Major
Fosinopril-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 a thiazide produces sequential nephron blockade and a strong diuretic effect. This can cause marked hypokalemia, hyponatremia, volume depletion and renal impairment. The ACE inhibitor adds to the risk of hypotension and renal dysfunction.
What this interaction means in plain words
Fosinopril-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.
Fosinopril-hydrochlorothiazide belongs to Cardiovascular; Metolazone belongs to Cardiovascular.
Why it happens
Additive inhibition of distal tubular sodium chloride reabsorption leading to excess natriuresis and potassium loss.
What to do
Avoid duplicate thiazide-type therapy where possible. If used, monitor electrolytes, creatinine, 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 Fosinopril-hydrochlorothiazide
- Aliskiren + Fosinopril-hydrochlorothiazide Contraindicated
- Dofetilide + Fosinopril-hydrochlorothiazide Contraindicated
- Fosinopril-hydrochlorothiazide + Protein a column Contraindicated
- Fosinopril-hydrochlorothiazide + Sacubitril / valsartan Contraindicated
- Aldesleukin + Fosinopril-hydrochlorothiazide Major
- Amifostine + Fosinopril-hydrochlorothiazide Major
Other interactions of Metolazone
Frequently asked questions
Can I take Fosinopril-hydrochlorothiazide with Metolazone?
MediHelp rates the interaction as major. Fosinopril-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 a thiazide produces sequential nephron blockade and a strong diuretic effect. This can cause marked hypokalemia, hyponatremia, volume depletion and renal impairment. The ACE inhibitor adds to the risk of hypotension and renal dysfunction.
How serious is the interaction between Fosinopril-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 duplicate thiazide-type therapy where possible. If used, monitor electrolytes, creatinine, weight and blood pressure closely.
What other medicines interact with Fosinopril-hydrochlorothiazide?
MediHelp also lists interactions of Fosinopril-hydrochlorothiazide with, for example, Aliskiren, Dofetilide, Protein a column. The full list is on the Fosinopril-hydrochlorothiazide page.
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