Drug interactions
Calcium acetate + Metolazone
Severity: Moderate
Calcium acetate 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
Thiazide-type diuretics such as metolazone reduce urinary calcium excretion, so taking calcium supplements or calcium-based binders with them can raise serum calcium. Hypercalcemia is more likely with high calcium doses, renal impairment or vitamin D therapy.
What this interaction means in plain words
Calcium acetate 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.
Calcium acetate belongs to Genitourinary; Metolazone belongs to Cardiovascular.
Why it happens
Metolazone enhances distal tubular calcium reabsorption, decreasing urinary calcium loss and adding to calcium intake.
What to do
Monitor serum calcium periodically, particularly in patients on high-dose calcium or vitamin D or with renal impairment. Reduce the calcium dose if hypercalcemia develops.
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 Calcium acetate
Frequently asked questions
Can I take Calcium acetate with Metolazone?
MediHelp rates the interaction as moderate. Calcium acetate 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. Thiazide-type diuretics such as metolazone reduce urinary calcium excretion, so taking calcium supplements or calcium-based binders with them can raise serum calcium. Hypercalcemia is more likely with high calcium doses, renal impairment or vitamin D therapy.
How serious is the interaction between Calcium acetate 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 calcium periodically, particularly in patients on high-dose calcium or vitamin D or with renal impairment. Reduce the calcium dose if hypercalcemia develops.
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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