Drug interactions
Chlorothiazide + Metolazone
Severity: Moderate
Chlorothiazide 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
Both are thiazide-type diuretics, so combining them duplicates therapy and increases loss of potassium, sodium and magnesium. Significant electrolyte disturbance and volume depletion may occur.
What this interaction means in plain words
Chlorothiazide 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.
Chlorothiazide belongs to Cardiovascular; Metolazone belongs to Cardiovascular.
Why it happens
Additive inhibition of distal tubule sodium-chloride reabsorption with increased renal potassium excretion.
What to do
Avoid combining two thiazide-type diuretics; if used, monitor electrolytes, renal function and blood pressure.
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 Metolazone
Other interactions of Chlorothiazide
Frequently asked questions
Can I take Chlorothiazide with Metolazone?
MediHelp rates the interaction as moderate. Chlorothiazide 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. Both are thiazide-type diuretics, so combining them duplicates therapy and increases loss of potassium, sodium and magnesium. Significant electrolyte disturbance and volume depletion may occur.
How serious is the interaction between Chlorothiazide 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: Avoid combining two thiazide-type diuretics; if used, monitor electrolytes, renal function and blood pressure.
What other medicines interact with Metolazone?
MediHelp also lists interactions of Metolazone with, for example, Amifostine, Amlodipine-hydrochlorothiazide-valsartan, Amlodipine-olmesartan-hydrochlorothiazide. The full list is on the Metolazone page.
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