Drug interactions
Clarithromycin + Theophylline
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.
Overview
Clarithromycin can increase theophylline serum concentrations; effect is usually modest but may be clinically relevant in susceptible patients.
Mechanism of action
Likely inhibition of theophylline metabolism (partial CYP3A4 contribution) and/or other pathways; theophylline is primarily cleared by CYP1A2 so the effect is typically small.
Clinical management
If used together, check a theophylline level 48–72 hours after starting or stopping clarithromycin; adjust theophylline dose based on levels and clinical response. Monitor for toxicity (nausea, vomiting, tremor, insomnia, tachyarrhythmias, seizures). Consider azithromycin as an alternative when appropriate.
Drug reference
References
- Clarithromycin: Drug Interactions (Theophylline) — Lexicomp
- Theophylline: Drug information (including drug interactions) — UpToDate
- Biaxin (clarithromycin) Prescribing Information — FDA Label
Frequently asked questions
Can I take Clarithromycin with Theophylline?
The interaction is rated: Moderate. Clarithromycin can increase theophylline serum concentrations; effect is usually modest but may be clinically relevant in susceptible patients.
How serious is the interaction between Clarithromycin and Theophylline?
The interaction is rated: Moderate. Evidence level: Moderate.
How is the interaction between Clarithromycin and Theophylline managed?
If used together, check a theophylline level 48–72 hours after starting or stopping clarithromycin; adjust theophylline dose based on levels and clinical response. Monitor for toxicity (nausea, vomiting, tremor, insomnia, tachyarrhythmias, seizures). Consider azithromycin as an alternative when appropriate.
Why do Clarithromycin and Theophylline interact?
Likely inhibition of theophylline metabolism (partial CYP3A4 contribution) and/or other pathways; theophylline is primarily cleared by CYP1A2 so the effect is typically small.
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