Drug interactions
Amlodipine-olmesartan-hydrochlorothiazide + Trimethoprim
Severity: Major
Amlodipine-olmesartan-hydrochlorothiazide 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, which reduces potassium excretion, and olmesartan also raises potassium. Together they can cause clinically significant hyperkalemia, particularly in older patients, with renal impairment, or with high doses. The hydrochlorothiazide component may partly offset it but does not remove the risk.
What this interaction means in plain words
Amlodipine-olmesartan-hydrochlorothiazide 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-hydrochlorothiazide belongs to Cardiovascular; Trimethoprim belongs to Anti Bacterial.
Why it happens
Trimethoprim blocks the epithelial sodium channel and, together with ARB-induced aldosterone suppression, reduces renal potassium excretion.
What to do
Check serum potassium and creatinine within a few days of starting trimethoprim, and avoid the combination in patients with renal impairment where possible. Consider an alternative antibiotic.
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-hydrochlorothiazide
- Aliskiren + Amlodipine-olmesartan-hydrochlorothiazide Contraindicated
- Amlodipine-olmesartan-hydrochlorothiazide + Dofetilide Contraindicated
- Amlodipine-olmesartan-hydrochlorothiazide + Sparsentan Contraindicated
- Acemetacin + Amlodipine-olmesartan-hydrochlorothiazide Major
- Aldesleukin + Amlodipine-olmesartan-hydrochlorothiazide Major
- Amifostine + Amlodipine-olmesartan-hydrochlorothiazide Major
Other interactions of Trimethoprim
Frequently asked questions
Can I take Amlodipine-olmesartan-hydrochlorothiazide with Trimethoprim?
MediHelp rates the interaction as major. Amlodipine-olmesartan-hydrochlorothiazide 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, which reduces potassium excretion, and olmesartan also raises potassium. Together they can cause clinically significant hyperkalemia, particularly in older patients, with renal impairment, or with high doses. The hydrochlorothiazide component may partly offset it but does not remove the risk.
How serious is the interaction between Amlodipine-olmesartan-hydrochlorothiazide 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 a few days of starting trimethoprim, and avoid the combination in patients with renal impairment where possible. Consider an alternative antibiotic.
What other medicines interact with Amlodipine-olmesartan-hydrochlorothiazide?
MediHelp also lists interactions of Amlodipine-olmesartan-hydrochlorothiazide with, for example, Aliskiren, Dofetilide, Sparsentan. The full list is on the Amlodipine-olmesartan-hydrochlorothiazide page.
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