Drug interactions
Amlodipine-valsartan + Trimethoprim
Severity: Major
Amlodipine-valsartan 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 blocks sodium channels in the distal nephron in a way similar to amiloride, reducing potassium excretion, and valsartan lowers aldosterone effect. Together they can cause clinically significant hyperkalemia, especially in elderly patients, those with renal impairment, or on high-dose trimethoprim.
What this interaction means in plain words
Amlodipine-valsartan 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-valsartan belongs to Cardiovascular; Trimethoprim belongs to Anti Bacterial.
Why it happens
Additive reduction of renal potassium excretion through ENaC blockade by trimethoprim and angiotensin receptor blockade.
What to do
Check serum potassium and creatinine within several days of starting trimethoprim and avoid the combination in renal impairment. Consider an alternative antibiotic when feasible.
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-valsartan
- Aliskiren + Amlodipine-valsartan Contraindicated
- Amlodipine-valsartan + Sparsentan Contraindicated
- Aldesleukin + Amlodipine-valsartan Major
- Amifostine + Amlodipine-valsartan Major
- Amiloride + Amlodipine-valsartan Major
- Amlodipine-valsartan + Benazepril Major
Other interactions of Trimethoprim
Frequently asked questions
Can I take Amlodipine-valsartan with Trimethoprim?
MediHelp rates the interaction as major. Amlodipine-valsartan 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 blocks sodium channels in the distal nephron in a way similar to amiloride, reducing potassium excretion, and valsartan lowers aldosterone effect. Together they can cause clinically significant hyperkalemia, especially in elderly patients, those with renal impairment, or on high-dose trimethoprim.
How serious is the interaction between Amlodipine-valsartan 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 avoid the combination in renal impairment. Consider an alternative antibiotic when feasible.
What other medicines interact with Amlodipine-valsartan?
MediHelp also lists interactions of Amlodipine-valsartan with, for example, Aliskiren, Sparsentan, Aldesleukin. The full list is on the Amlodipine-valsartan page.
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