Drug interactions
Eplerenone + Trimethoprim
Severity: Major
Eplerenone and Trimethoprim: major interaction.
Last updated Sources: UK SmPC
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 drugs promote potassium retention, so the combination can cause serious hyperkalemia. The risk is higher with high-dose trimethoprim, renal impairment, diabetes, older age or other potassium-raising drugs.
What this interaction means in plain words
Eplerenone and Trimethoprim can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for.
Eplerenone belongs to Cardiovascular; Trimethoprim belongs to Anti Bacterial.
Why it happens
Trimethoprim blocks the epithelial sodium channel in the distal nephron, while eplerenone blocks aldosterone receptors, giving additive reduction of potassium excretion.
What to do
Avoid the combination where an alternative antibiotic exists. If used, check potassium and creatinine within several days and periodically afterwards.
What to ask your pharmacist
- Does the benefit of taking both outweigh the risk in my case?
- Do I need any blood test, ECG or other check while on both?
- What early warning signs should I watch for, and what should I do if they appear?
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References
Other interactions of Eplerenone
- Amiloride + Eplerenone Contraindicated
- Atazanavir + Eplerenone Contraindicated
- Clarithromycin + Eplerenone Contraindicated
- Cobicistat + Eplerenone Contraindicated
- Elvitegravir / cobicistat / emtricitabine / tenofovir df + Eplerenone Contraindicated
- Ensitrelvir + Eplerenone Contraindicated
Other interactions of Trimethoprim
Frequently asked questions
Can I take Eplerenone with Trimethoprim?
MediHelp rates the interaction as major. Eplerenone and Trimethoprim can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for. Both drugs promote potassium retention, so the combination can cause serious hyperkalemia. The risk is higher with high-dose trimethoprim, renal impairment, diabetes, older age or other potassium-raising drugs.
How serious is the interaction between Eplerenone and Trimethoprim?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid the combination where an alternative antibiotic exists. If used, check potassium and creatinine within several days and periodically afterwards.
What other medicines interact with Eplerenone?
MediHelp also lists interactions of Eplerenone with, for example, Amiloride, Atazanavir, Clarithromycin. The full list is on the Eplerenone page.
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