Drug interactions
Lapatinib + Theophylline
Severity: Minor
Lapatinib and Theophylline: minor 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
Lapatinib inhibits some CYP enzymes, but theophylline is mainly metabolized by CYP1A2, so a clinically important interaction is not established. Theoretical increases in theophylline exposure are possible.
What this interaction means in plain words
Lapatinib and Theophylline have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised.
Lapatinib belongs to Oncology; Theophylline belongs to Respiratory.
Why it happens
Lapatinib inhibits CYP3A4 and CYP2C8, which play a minor role in theophylline metabolism.
What to do
No routine dose change is needed. Check theophylline levels if signs of toxicity appear.
What to ask your pharmacist
- Is there anything I should notice while taking both?
- Do I need to tell my doctor at the next visit?
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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 Lapatinib
- Dofetilide + Lapatinib Contraindicated
- Ibutilide + Lapatinib Contraindicated
- Lapatinib + Pimozide Contraindicated
- Lapatinib + Saquinavir Contraindicated
- Lapatinib + Thioridazine Contraindicated
- Adagrasib + Lapatinib Major
Frequently asked questions
Can I take Lapatinib with Theophylline?
MediHelp rates the interaction as minor. Lapatinib and Theophylline have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised. Lapatinib inhibits some CYP enzymes, but theophylline is mainly metabolized by CYP1A2, so a clinically important interaction is not established. Theoretical increases in theophylline exposure are possible.
How serious is the interaction between Lapatinib and Theophylline?
MediHelp rates it minor, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: No routine dose change is needed. Check theophylline levels if signs of toxicity appear.
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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