Drug interactions
Diltiazem + Erlotinib
Severity: Moderate
Diltiazem and Erlotinib: 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
Diltiazem may increase erlotinib exposure, raising the risk of rash, diarrhea and other dose-related adverse effects.
What this interaction means in plain words
Diltiazem and Erlotinib 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.
Diltiazem belongs to Cardiovascular; Erlotinib belongs to Oncology.
Why it happens
Diltiazem inhibits CYP3A4, the main enzyme metabolizing erlotinib.
What to do
Monitor for erlotinib toxicity such as severe diarrhea and rash, and reduce the erlotinib dose stepwise if needed.
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 Diltiazem
- Diltiazem + Flibanserin Contraindicated
- Diltiazem + Ivabradine Contraindicated
- Diltiazem + Lomitapide Contraindicated
- Diltiazem + Lonafarnib Contraindicated
- Acebutolol + Diltiazem Major
- Alfentanil + Diltiazem Major
Other interactions of Erlotinib
- Amobarbital + Erlotinib Major
- Apalutamide + Erlotinib Major
- Carbamazepine + Erlotinib Major
- Cobicistat + Erlotinib Major
- Darunavir + Erlotinib Major
- Dexlansoprazole + Erlotinib Major
Frequently asked questions
Can I take Diltiazem with Erlotinib?
MediHelp rates the interaction as moderate. Diltiazem and Erlotinib 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. Diltiazem may increase erlotinib exposure, raising the risk of rash, diarrhea and other dose-related adverse effects.
How serious is the interaction between Diltiazem and Erlotinib?
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 for erlotinib toxicity such as severe diarrhea and rash, and reduce the erlotinib dose stepwise if needed.
What other medicines interact with Diltiazem?
MediHelp also lists interactions of Diltiazem with, for example, Flibanserin, Ivabradine, Lomitapide. The full list is on the Diltiazem page.
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