Drug interactions
Amlodipine-olmesartan + Trimethoprim
Severity: Major
Amlodipine-olmesartan 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
Trimethoprim reduces renal potassium excretion, and combined with an angiotensin receptor blocker it can cause clinically significant hyperkalemia. The risk is higher in elderly patients, those with renal impairment, and with high-dose trimethoprim.
What this interaction means in plain words
Amlodipine-olmesartan 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.
Amlodipine-olmesartan belongs to Cardiovascular; Trimethoprim belongs to Anti Bacterial.
Why it happens
Trimethoprim blocks epithelial sodium channels in the distal nephron, and olmesartan reduces aldosterone-mediated potassium excretion, giving additive hyperkalemia.
What to do
Check serum potassium and creatinine within several days of starting trimethoprim and consider an alternative antibiotic in high-risk patients. Avoid additional potassium-raising agents.
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 Amlodipine-olmesartan
- Aliskiren + Amlodipine-olmesartan Contraindicated
- Amlodipine-olmesartan + Sparsentan Contraindicated
- Amifostine + Amlodipine-olmesartan Major
- Amiloride + Amlodipine-olmesartan Major
- Amlodipine-olmesartan + Benazepril Major
- Amlodipine-olmesartan + Captopril Major
Other interactions of Trimethoprim
Frequently asked questions
Can I take Amlodipine-olmesartan with Trimethoprim?
MediHelp rates the interaction as major. Amlodipine-olmesartan 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. Trimethoprim reduces renal potassium excretion, and combined with an angiotensin receptor blocker it can cause clinically significant hyperkalemia. The risk is higher in elderly patients, those with renal impairment, and with high-dose trimethoprim.
How serious is the interaction between Amlodipine-olmesartan 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 serum potassium and creatinine within several days of starting trimethoprim and consider an alternative antibiotic in high-risk patients. Avoid additional potassium-raising agents.
What other medicines interact with Amlodipine-olmesartan?
MediHelp also lists interactions of Amlodipine-olmesartan with, for example, Aliskiren, Sparsentan, Amifostine. The full list is on the Amlodipine-olmesartan page.
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