Drug interactions
Diltiazem + Ivacaftor
Severity: Moderate
Diltiazem and Ivacaftor: 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 increases ivacaftor exposure, which may increase adverse effects such as headache, dizziness and elevated liver enzymes.
What this interaction means in plain words
Diltiazem and Ivacaftor 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; Ivacaftor belongs to Miscellaneous.
Why it happens
Diltiazem inhibits CYP3A4-mediated ivacaftor metabolism.
What to do
Reduce the ivacaftor dose according to the product labeling for moderate CYP3A inhibitors and monitor liver tests.
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 Ivacaftor
- Ensitrelvir + Ivacaftor Contraindicated
- Apalutamide + Ivacaftor Major
- Carbamazepine + Ivacaftor Major
- Clarithromycin + Ivacaftor Major
- Efavirenz + Ivacaftor Major
- Enzalutamide + Ivacaftor Major
Frequently asked questions
Can I take Diltiazem with Ivacaftor?
MediHelp rates the interaction as moderate. Diltiazem and Ivacaftor 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 increases ivacaftor exposure, which may increase adverse effects such as headache, dizziness and elevated liver enzymes.
How serious is the interaction between Diltiazem and Ivacaftor?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Reduce the ivacaftor dose according to the product labeling for moderate CYP3A inhibitors and monitor liver tests.
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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