Drug interactions
Clarithromycin + Rifampin
Severity: Major
Clarithromycin and Rifampin: 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
Rifampin strongly induces CYP3A4 and lowers clarithromycin concentrations while raising the active 14-hydroxy metabolite. Antibacterial efficacy, for example in mycobacterial infection, may be reduced.
What this interaction means in plain words
Clarithromycin and Rifampin 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.
Why it happens
Rifampin induces CYP3A4, accelerating clarithromycin metabolism.
What to do
Avoid the combination where possible, or consider an alternative such as azithromycin. If it is used for mycobacterial therapy, monitor clinical response.
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 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 Rifampin?
MediHelp rates the interaction as major. Clarithromycin and Rifampin 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. Rifampin strongly induces CYP3A4 and lowers clarithromycin concentrations while raising the active 14-hydroxy metabolite. Antibacterial efficacy, for example in mycobacterial infection, may be reduced.
How serious is the interaction between Clarithromycin and Rifampin?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid the combination where possible, or consider an alternative such as azithromycin. If it is used for mycobacterial therapy, monitor clinical response.
What other medicines interact with Clarithromycin?
MediHelp also lists interactions of Clarithromycin with, for example, Astemizole, Avanafil, Cisapride. The full list is on the Clarithromycin page.
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