Drug interactions
Clarithromycin + Vardenafil
Severity: Major
Clarithromycin and Vardenafil: major interaction.
Last updated Sources: US FDA label
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
Clarithromycin strongly inhibits CYP3A4 and markedly increases vardenafil exposure, and both drugs can prolong the QT interval. This raises the risk of hypotension and torsades de pointes.
What this interaction means in plain words
Clarithromycin and Vardenafil 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.
Clarithromycin belongs to Anti Bacterial; Vardenafil belongs to Genitourinary.
Why it happens
CYP3A4 inhibition increases vardenafil levels, together with additive QTc prolongation.
What to do
Limit vardenafil to a maximum of 2.5 mg in a 24-hour period per labeling, or use a non-macrolide antibiotic. Obtain an ECG if QT risk factors are present.
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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References
Other interactions of Vardenafil
- Amyl nitrite + Vardenafil Contraindicated
- Glyceryl trinitrate pr + Vardenafil Contraindicated
- Isosorbide dinitrate + Vardenafil Contraindicated
- Isosorbide mononitrate + Vardenafil Contraindicated
- Nicorandil + Vardenafil Contraindicated
- Nitroglycerin po + Vardenafil Contraindicated
Other interactions of Clarithromycin
- Astemizole + Clarithromycin Contraindicated
- Avanafil + Clarithromycin Contraindicated
- Cisapride + Clarithromycin Contraindicated
- Clarithromycin + Colchicine Contraindicated
- Clarithromycin + Conivaptan Contraindicated
- Clarithromycin + Dihydroergotamine Contraindicated
Frequently asked questions
Can I take Clarithromycin with Vardenafil?
MediHelp rates the interaction as major. Clarithromycin and Vardenafil 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. Clarithromycin strongly inhibits CYP3A4 and markedly increases vardenafil exposure, and both drugs can prolong the QT interval. This raises the risk of hypotension and torsades de pointes.
How serious is the interaction between Clarithromycin and Vardenafil?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Limit vardenafil to a maximum of 2.5 mg in a 24-hour period per labeling, or use a non-macrolide antibiotic. Obtain an ECG if QT risk factors are present.
What other medicines interact with Vardenafil?
MediHelp also lists interactions of Vardenafil with, for example, Amyl nitrite, Glyceryl trinitrate pr, Isosorbide dinitrate. The full list is on the Vardenafil page.
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