Drug interactions
Moexipril + Trimethoprim
Severity: Major
Moexipril 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 can raise serum potassium, and the combination can cause clinically significant hyperkalemia, particularly in older patients and those with renal impairment or diabetes. Severe cases with arrhythmia have been reported.
What this interaction means in plain words
Moexipril 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.
Moexipril belongs to Cardiovascular; Trimethoprim belongs to Anti Bacterial.
Why it happens
Trimethoprim blocks epithelial sodium channels in the distal nephron, while ACE inhibition reduces aldosterone, both impairing potassium excretion.
What to do
Check potassium and creatinine within several days of starting trimethoprim and avoid the combination in renal impairment if possible. Choose an alternative antibiotic in high-risk patients.
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 Moexipril
- Aliskiren + Moexipril Contraindicated
- Moexipril + Protein a column Contraindicated
- Moexipril + Sacubitril / valsartan Contraindicated
- Moexipril + Sacubitril-valsartan Contraindicated
- Amifostine + Moexipril Major
- Amiloride + Moexipril Major
Other interactions of Trimethoprim
Frequently asked questions
Can I take Moexipril with Trimethoprim?
MediHelp rates the interaction as major. Moexipril 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 can raise serum potassium, and the combination can cause clinically significant hyperkalemia, particularly in older patients and those with renal impairment or diabetes. Severe cases with arrhythmia have been reported.
How serious is the interaction between Moexipril 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: Check potassium and creatinine within several days of starting trimethoprim and avoid the combination in renal impairment if possible. Choose an alternative antibiotic in high-risk patients.
What other medicines interact with Moexipril?
MediHelp also lists interactions of Moexipril with, for example, Aliskiren, Protein a column, Sacubitril / valsartan. The full list is on the Moexipril page.
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