Drug interactions
Chloramphenicol + Sildenafil
Severity: Moderate
Chloramphenicol and Sildenafil: moderate 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
Chloramphenicol may inhibit CYP3A4 and raise sildenafil concentrations, increasing the risk of headache, flushing, hypotension and visual disturbance. The inhibition is considered weaker and less well documented than that of azole antifungals or macrolides.
What this interaction means in plain words
Chloramphenicol and Sildenafil can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken.
Chloramphenicol belongs to Anti Bacterial; Sildenafil belongs to Genitourinary.
Why it happens
Inhibition of CYP3A4-mediated metabolism of sildenafil.
What to do
Consider starting with a lower sildenafil dose, such as 25 mg for erectile dysfunction, and monitor for adverse effects and blood pressure.
What to ask your pharmacist
- Should I take them at different times of day?
- Does the dose of either medicine need to change?
- Is there anything I should avoid, such as alcohol or certain foods, while on both?
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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 Chloramphenicol
Frequently asked questions
Can I take Chloramphenicol with Sildenafil?
MediHelp rates the interaction as moderate. Chloramphenicol and Sildenafil can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken. Chloramphenicol may inhibit CYP3A4 and raise sildenafil concentrations, increasing the risk of headache, flushing, hypotension and visual disturbance. The inhibition is considered weaker and less well documented than that of azole antifungals or macrolides.
How serious is the interaction between Chloramphenicol and Sildenafil?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Consider starting with a lower sildenafil dose, such as 25 mg for erectile dysfunction, and monitor for adverse effects and blood pressure.
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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