Drug interactions
Bosentan + Erythromycin
Severity: Major
Bosentan and Erythromycin: 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
Bosentan induces CYP3A4 and may lower erythromycin concentrations, potentially reducing antibacterial effect. Erythromycin in turn inhibits CYP3A4 and can raise bosentan concentrations, increasing the risk of hypotension, headache and liver toxicity.
What this interaction means in plain words
Bosentan and Erythromycin 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.
Bosentan belongs to Miscellaneous; Erythromycin belongs to Anti Bacterial.
Why it happens
Bosentan induces CYP3A4 while erythromycin inhibits CYP3A4 and bosentan metabolism, producing bidirectional pharmacokinetic changes.
What to do
Use an alternative antibiotic that is not a CYP3A4 substrate or inhibitor where possible. If combined, monitor liver enzymes, blood pressure and clinical response of the infection.
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 Erythromycin
- Conivaptan + Erythromycin Contraindicated
- Dihydroergotamine intranasal + Erythromycin Contraindicated
- Dihydroergotamine + Erythromycin Contraindicated
- Domperidone + Erythromycin Contraindicated
- Dronedarone + Erythromycin Contraindicated
- Droperidol + Erythromycin Contraindicated
Other interactions of Bosentan
- Bosentan + Cyclosporin Contraindicated
- Bosentan + Glibenclamide Contraindicated
- Bosentan + Glyburide-metformin Contraindicated
- Bosentan + Lonafarnib Contraindicated
- Bosentan + Sparsentan Contraindicated
- Artemether / lumefantrine + Bosentan Major
Frequently asked questions
Can I take Bosentan with Erythromycin?
MediHelp rates the interaction as major. Bosentan and Erythromycin 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. Bosentan induces CYP3A4 and may lower erythromycin concentrations, potentially reducing antibacterial effect. Erythromycin in turn inhibits CYP3A4 and can raise bosentan concentrations, increasing the risk of hypotension, headache and liver toxicity.
How serious is the interaction between Bosentan and Erythromycin?
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 an alternative antibiotic that is not a CYP3A4 substrate or inhibitor where possible. If combined, monitor liver enzymes, blood pressure and clinical response of the infection.
What other medicines interact with Erythromycin?
MediHelp also lists interactions of Erythromycin with, for example, Conivaptan, Dihydroergotamine intranasal, Dihydroergotamine. The full list is on the Erythromycin page.
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