Drug interactions
Losartan + Metronidazole
Severity: Minor
Losartan and Metronidazole: 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
Losartan is partly converted to its active metabolite E-3174 via CYP2C9 and CYP3A4. Metronidazole could theoretically alter this conversion, but there is no convincing evidence of a clinically important change in blood pressure control.
What this interaction means in plain words
Losartan and Metronidazole have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised.
Losartan belongs to Cardiovascular; Metronidazole belongs to Anti Parasitic.
Why it happens
Theoretical weak inhibition of CYP2C9 by metronidazole may alter formation of the active metabolite of losartan.
What to do
No empirical dose change is needed; check blood pressure if the patient receives a prolonged course of metronidazole.
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 Metronidazole
- Ethanol + Metronidazole Contraindicated
- Metronidazole + Pimozide Contraindicated
- Amiodarone + Metronidazole Major
- Disulfiram + Metronidazole Major
- Ergotamine + Metronidazole Major
- Lomitapide + Metronidazole 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 Losartan with Metronidazole?
MediHelp rates the interaction as minor. Losartan and Metronidazole have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised. Losartan is partly converted to its active metabolite E-3174 via CYP2C9 and CYP3A4. Metronidazole could theoretically alter this conversion, but there is no convincing evidence of a clinically important change in blood pressure control.
How serious is the interaction between Losartan and Metronidazole?
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 empirical dose change is needed; check blood pressure if the patient receives a prolonged course of metronidazole.
What other medicines interact with Metronidazole?
MediHelp also lists interactions of Metronidazole with, for example, Ethanol, Pimozide, Amiodarone. The full list is on the Metronidazole page.
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