Drug interactions
Hydrochlorothiazide-irbesartan + Metolazone
Severity: Moderate
Hydrochlorothiazide-irbesartan and Metolazone: moderate 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 adds a second thiazide-type diuretic to hydrochlorothiazide, producing sequential nephron blockade with a much stronger diuresis. This can cause marked hypokalemia, hyponatremia, volume depletion, hypotension and renal impairment. The potassium-sparing effect of irbesartan only partly offsets the loss.
What this interaction means in plain words
Hydrochlorothiazide-irbesartan and Metolazone can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken.
Hydrochlorothiazide-irbesartan belongs to Cardiovascular; Metolazone belongs to Cardiovascular.
Why it happens
Additive inhibition of sodium chloride reabsorption in the distal tubule leads to increased urinary loss of potassium, sodium and water.
What to do
Monitor serum electrolytes, renal function, blood pressure and weight within the first days of combined use and periodically thereafter. Use the lowest effective metolazone dose and correct potassium and magnesium deficits.
What to ask your pharmacist
- Should I take them at different times of day?
- Does the dose of either medicine need to change?
- Is there anything I should avoid, such as alcohol or certain foods, while on both?
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Other interactions of Hydrochlorothiazide-irbesartan
- Aliskiren + Hydrochlorothiazide-irbesartan Contraindicated
- Dofetilide + Hydrochlorothiazide-irbesartan Contraindicated
- Hydrochlorothiazide-irbesartan + Sparsentan Contraindicated
- Aldesleukin + Hydrochlorothiazide-irbesartan Major
- Amifostine + Hydrochlorothiazide-irbesartan Major
- Amiloride + Hydrochlorothiazide-irbesartan Major
Other interactions of Metolazone
Frequently asked questions
Can I take Hydrochlorothiazide-irbesartan with Metolazone?
MediHelp rates the interaction as moderate. Hydrochlorothiazide-irbesartan and Metolazone can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken. Metolazone adds a second thiazide-type diuretic to hydrochlorothiazide, producing sequential nephron blockade with a much stronger diuresis. This can cause marked hypokalemia, hyponatremia, volume depletion, hypotension and renal impairment. The potassium-sparing effect of irbesartan only partly offsets the loss.
How serious is the interaction between Hydrochlorothiazide-irbesartan and Metolazone?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor serum electrolytes, renal function, blood pressure and weight within the first days of combined use and periodically thereafter. Use the lowest effective metolazone dose and correct potassium and magnesium deficits.
What other medicines interact with Hydrochlorothiazide-irbesartan?
MediHelp also lists interactions of Hydrochlorothiazide-irbesartan with, for example, Aliskiren, Dofetilide, Sparsentan. The full list is on the Hydrochlorothiazide-irbesartan page.
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