Drug interactions
Crizotinib + Theophylline
Severity: Moderate
Crizotinib and Theophylline: 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
Crizotinib inhibits CYP3A4, which could modestly raise theophylline concentrations. Since theophylline has a narrow therapeutic index, toxicity such as arrhythmia, tremor or seizures is possible.
What this interaction means in plain words
Crizotinib and Theophylline 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.
Crizotinib belongs to Oncology; Theophylline belongs to Respiratory.
Why it happens
Crizotinib inhibits CYP3A4, a minor pathway of theophylline metabolism.
What to do
Monitor serum theophylline concentrations and signs of toxicity, and reduce the theophylline dose if levels rise.
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 Theophylline
- Riociguat + Theophylline Contraindicated
- Adenosine + Theophylline Major
- Apalutamide + Theophylline Major
- Bupropion + Theophylline Major
- Carvedilol + Theophylline Major
- Cimetidine + Theophylline Major
Other interactions of Crizotinib
- Crizotinib + Flibanserin Contraindicated
- Crizotinib + Lomitapide Contraindicated
- Crizotinib + Lonafarnib Contraindicated
- Crizotinib + Pimozide Contraindicated
- Crizotinib + Saquinavir Contraindicated
- Crizotinib + Thioridazine Contraindicated
Frequently asked questions
Can I take Crizotinib with Theophylline?
MediHelp rates the interaction as moderate. Crizotinib and Theophylline 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. Crizotinib inhibits CYP3A4, which could modestly raise theophylline concentrations. Since theophylline has a narrow therapeutic index, toxicity such as arrhythmia, tremor or seizures is possible.
How serious is the interaction between Crizotinib and Theophylline?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor serum theophylline concentrations and signs of toxicity, and reduce the theophylline dose if levels rise.
What other medicines interact with Theophylline?
MediHelp also lists interactions of Theophylline with, for example, Riociguat, Adenosine, Apalutamide. The full list is on the Theophylline page.
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