Drug interactions
Clarithromycin + Sildenafil
Severity: Major
Clarithromycin and Sildenafil: 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 is a strong CYP3A4 inhibitor and increases sildenafil exposure, raising the risk of hypotension, priapism, visual disturbance and other dose-related adverse effects.
What this interaction means in plain words
Clarithromycin and Sildenafil 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; Sildenafil belongs to Genitourinary.
Why it happens
Inhibition of CYP3A4 reduces first-pass and systemic clearance of sildenafil.
What to do
Use a reduced starting sildenafil dose (25 mg) for erectile dysfunction and avoid the combination in pulmonary arterial hypertension. Consider an alternative antibiotic such as azithromycin.
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 Sildenafil
- Amyl nitrite + Sildenafil Contraindicated
- Atazanavir + Sildenafil Contraindicated
- Cobicistat + Sildenafil Contraindicated
- Elvitegravir / cobicistat / emtricitabine / tenofovir df + Sildenafil Contraindicated
- Glyceryl trinitrate pr + Sildenafil Contraindicated
- Isosorbide dinitrate + Sildenafil 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 Sildenafil?
MediHelp rates the interaction as major. Clarithromycin and Sildenafil 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 is a strong CYP3A4 inhibitor and increases sildenafil exposure, raising the risk of hypotension, priapism, visual disturbance and other dose-related adverse effects.
How serious is the interaction between Clarithromycin and Sildenafil?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Use a reduced starting sildenafil dose (25 mg) for erectile dysfunction and avoid the combination in pulmonary arterial hypertension. Consider an alternative antibiotic such as azithromycin.
What other medicines interact with Sildenafil?
MediHelp also lists interactions of Sildenafil with, for example, Amyl nitrite, Atazanavir, Cobicistat. The full list is on the Sildenafil page.
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