Drug interactions
Metolazone + Tolfenamic acid
Severity: Moderate
Metolazone and Tolfenamic acid: 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
NSAIDs such as tolfenamic acid can reduce the diuretic and antihypertensive effect of metolazone and raise the risk of renal impairment, especially with volume depletion or underlying kidney disease.
What this interaction means in plain words
Metolazone and Tolfenamic acid 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 belongs to Cardiovascular; Tolfenamic acid belongs to Musculoskeletal.
Why it happens
NSAID inhibition of renal prostaglandin synthesis causes sodium and water retention and reduced renal perfusion, opposing diuretic action.
What to do
Monitor blood pressure, fluid status, creatinine and electrolytes, and use the lowest effective NSAID dose for the shortest time. Consider paracetamol as an alternative.
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 Tolfenamic acid
Frequently asked questions
Can I take Metolazone with Tolfenamic acid?
MediHelp rates the interaction as moderate. Metolazone and Tolfenamic acid 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. NSAIDs such as tolfenamic acid can reduce the diuretic and antihypertensive effect of metolazone and raise the risk of renal impairment, especially with volume depletion or underlying kidney disease.
How serious is the interaction between Metolazone and Tolfenamic acid?
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 blood pressure, fluid status, creatinine and electrolytes, and use the lowest effective NSAID dose for the shortest time. Consider paracetamol as an alternative.
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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