Drug interactions
Cimetidine + Losartan
Severity: Minor
Cimetidine and Losartan: minor 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
Cimetidine may modestly increase losartan exposure and reduce formation of its active metabolite E-3174. The net effect on blood pressure control is small and not well established.
What this interaction means in plain words
Cimetidine and Losartan have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised.
Cimetidine belongs to Gastrointestinal Tract; Losartan belongs to Cardiovascular.
Why it happens
Cimetidine inhibits CYP2C9 and CYP3A4 involved in converting losartan to E-3174.
What to do
No dose adjustment is routinely needed; check blood pressure response after starting or stopping cimetidine.
What to ask your pharmacist
- Is there anything I should notice while taking both?
- Do I need to tell my doctor at the next visit?
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Other interactions of Cimetidine
- Cimetidine + Dofetilide Contraindicated
- Cimetidine + Fezolinetant Contraindicated
- Alfentanil + Cimetidine Major
- Atazanavir + Cimetidine Major
- Carmustine + Cimetidine Major
- Cimetidine + Citalopram Major
Other interactions of Losartan
- Aliskiren + Losartan Contraindicated
- Losartan + Sparsentan Contraindicated
- Amifostine + Losartan Major
- Amiloride + Losartan Major
- Amlodipine-benazepril + Losartan Major
- Amlodipine-hydrochlorothiazide-valsartan + Losartan Major
Frequently asked questions
Can I take Cimetidine with Losartan?
MediHelp rates the interaction as minor. Cimetidine and Losartan have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised. Cimetidine may modestly increase losartan exposure and reduce formation of its active metabolite E-3174. The net effect on blood pressure control is small and not well established.
How serious is the interaction between Cimetidine and Losartan?
MediHelp rates it minor, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: No dose adjustment is routinely needed; check blood pressure response after starting or stopping cimetidine.
What other medicines interact with Cimetidine?
MediHelp also lists interactions of Cimetidine with, for example, Dofetilide, Fezolinetant, Alfentanil. The full list is on the Cimetidine page.
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