Drug interactions
Perindopril + Trimethoprim
Severity: Major
Perindopril and Trimethoprim: major 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 drugs reduce potassium excretion, and combined use can cause clinically important hyperkalemia. Cases of severe hyperkalemia have occurred, particularly in older patients and those with renal impairment.
What this interaction means in plain words
Perindopril 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.
Perindopril belongs to Cardiovascular; Trimethoprim belongs to Anti Bacterial.
Why it happens
Trimethoprim blocks epithelial sodium channels in the distal nephron, and ACE inhibition lowers aldosterone, both decreasing potassium excretion.
What to do
Avoid if possible, particularly in the elderly or with renal impairment, and choose an alternative antibiotic. If necessary, check serum potassium and renal function within several days of starting.
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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Other interactions of Perindopril
- Aliskiren + Perindopril Contraindicated
- Perindopril + Protein a column Contraindicated
- Perindopril + Sacubitril / valsartan Contraindicated
- Perindopril + Sacubitril-valsartan Contraindicated
- Amifostine + Perindopril Major
- Amiloride + Perindopril Major
Other interactions of Trimethoprim
Frequently asked questions
Can I take Perindopril with Trimethoprim?
MediHelp rates the interaction as major. Perindopril 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 reduce potassium excretion, and combined use can cause clinically important hyperkalemia. Cases of severe hyperkalemia have occurred, particularly in older patients and those with renal impairment.
How serious is the interaction between Perindopril 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 if possible, particularly in the elderly or with renal impairment, and choose an alternative antibiotic. If necessary, check serum potassium and renal function within several days of starting.
What other medicines interact with Perindopril?
MediHelp also lists interactions of Perindopril with, for example, Aliskiren, Protein a column, Sacubitril / valsartan. The full list is on the Perindopril page.
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