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Drug interactions

Cyclopenthiazide + Metolazone

Severity: Moderate

Cyclopenthiazide 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 potassium, sodium and magnesium loss. Marked electrolyte disturbances and hypovolemia can occur.

What this interaction means in plain words

Cyclopenthiazide 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.

Evidence level: Moderate

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?

Bring a full list of your medicines, including over-the-counter products, supplements and herbal remedies, to every pharmacy visit.

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Frequently asked questions

Can I take Cyclopenthiazide with Metolazone?

MediHelp rates the interaction as moderate. Cyclopenthiazide 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 potassium, sodium and magnesium loss. Marked electrolyte disturbances and hypovolemia can occur.

How serious is the interaction between Cyclopenthiazide 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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