Drug interactions
Diltiazem + Larotrectinib
Severity: Moderate
Diltiazem and Larotrectinib: 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
Larotrectinib is a CYP3A4 substrate, so diltiazem may increase its concentrations and the risk of adverse effects such as hepatotoxicity, dizziness, and neurotoxicity. The label advises avoiding strong inhibitors, and moderate inhibitors are less well studied.
What this interaction means in plain words
Diltiazem and Larotrectinib 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; Larotrectinib belongs to Oncology.
Why it happens
Diltiazem inhibits CYP3A4 metabolism of larotrectinib.
What to do
Monitor liver enzymes and neurologic adverse effects, or choose an alternative to diltiazem.
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 Larotrectinib
Frequently asked questions
Can I take Diltiazem with Larotrectinib?
MediHelp rates the interaction as moderate. Diltiazem and Larotrectinib 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. Larotrectinib is a CYP3A4 substrate, so diltiazem may increase its concentrations and the risk of adverse effects such as hepatotoxicity, dizziness, and neurotoxicity. The label advises avoiding strong inhibitors, and moderate inhibitors are less well studied.
How serious is the interaction between Diltiazem and Larotrectinib?
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 liver enzymes and neurologic adverse effects, or choose an alternative to diltiazem.
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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