Drug interactions
Cimetidine + Hydrochlorothiazide-losartan
Severity: Minor
Cimetidine and Hydrochlorothiazide-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 raise losartan exposure and reduce formation of its active metabolite. The net clinical effect is small.
What this interaction means in plain words
Cimetidine and Hydrochlorothiazide-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; Hydrochlorothiazide-losartan belongs to Cardiovascular.
Why it happens
Cimetidine weakly inhibits hepatic CYP-mediated losartan metabolism.
What to do
No dose change usually needed; monitor blood pressure response when cimetidine is started or stopped.
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 Hydrochlorothiazide-losartan
- Aliskiren + Hydrochlorothiazide-losartan Contraindicated
- Dofetilide + Hydrochlorothiazide-losartan Contraindicated
- Hydrochlorothiazide-losartan + Sparsentan Contraindicated
- Aceclofenac + Hydrochlorothiazide-losartan Major
- Aldesleukin + Hydrochlorothiazide-losartan Major
- Amifostine + Hydrochlorothiazide-losartan Major
Other interactions of Cimetidine
- Cimetidine + Dofetilide Contraindicated
- Cimetidine + Fezolinetant Contraindicated
- Alfentanil + Cimetidine Major
- Atazanavir + Cimetidine Major
- Carmustine + Cimetidine Major
- Cimetidine + Citalopram Major
Frequently asked questions
Can I take Cimetidine with Hydrochlorothiazide-losartan?
MediHelp rates the interaction as minor. Cimetidine and Hydrochlorothiazide-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 raise losartan exposure and reduce formation of its active metabolite. The net clinical effect is small.
How serious is the interaction between Cimetidine and Hydrochlorothiazide-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 change usually needed; monitor blood pressure response when cimetidine is started or stopped.
What other medicines interact with Hydrochlorothiazide-losartan?
MediHelp also lists interactions of Hydrochlorothiazide-losartan with, for example, Aliskiren, Dofetilide, Sparsentan. The full list is on the Hydrochlorothiazide-losartan page.
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