Drug interactions
Metronidazole + Tadalafil
Severity: Minor
Metronidazole and Tadalafil: 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
Metronidazole has little clinically meaningful effect on CYP3A4, and no established interaction with tadalafil exists. The legacy suggestion of raised tadalafil levels is not supported by good evidence.
What this interaction means in plain words
Metronidazole and Tadalafil have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised.
Metronidazole belongs to Anti Parasitic; Tadalafil belongs to Genitourinary.
Why it happens
No established mechanism; any CYP3A4 effect of metronidazole is weak and unproven.
What to do
No action is needed beyond usual monitoring for tadalafil adverse effects.
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 Tadalafil
- Amyl nitrite + Tadalafil Contraindicated
- Isosorbide dinitrate + Tadalafil Contraindicated
- Isosorbide mononitrate + Tadalafil Contraindicated
- Nitroglycerin po + Tadalafil Contraindicated
- Nitroglycerin rectal + Tadalafil Contraindicated
- Nitroglycerin sublingual + Tadalafil Contraindicated
Other interactions of Metronidazole
- Ethanol + Metronidazole Contraindicated
- Metronidazole + Pimozide Contraindicated
- Amiodarone + Metronidazole Major
- Disulfiram + Metronidazole Major
- Ergotamine + Metronidazole Major
- Lomitapide + Metronidazole Major
Frequently asked questions
Can I take Metronidazole with Tadalafil?
MediHelp rates the interaction as minor. Metronidazole and Tadalafil have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised. Metronidazole has little clinically meaningful effect on CYP3A4, and no established interaction with tadalafil exists. The legacy suggestion of raised tadalafil levels is not supported by good evidence.
How serious is the interaction between Metronidazole and Tadalafil?
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 action is needed beyond usual monitoring for tadalafil adverse effects.
What other medicines interact with Tadalafil?
MediHelp also lists interactions of Tadalafil with, for example, Amyl nitrite, Isosorbide dinitrate, Isosorbide mononitrate. The full list is on the Tadalafil page.
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