Drug interactions
Diltiazem + Nifedipine
Severity: Moderate
Diltiazem and Nifedipine: 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 raises nifedipine exposure, which can cause excessive vasodilation with hypotension, flushing, headache, peripheral edema and reflex tachycardia. Combining two calcium channel blockers also produces additive blood pressure lowering.
What this interaction means in plain words
Diltiazem and Nifedipine 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; Nifedipine belongs to Cardiovascular.
Why it happens
Diltiazem inhibits CYP3A4, reducing first-pass and systemic metabolism of nifedipine, and the two agents have additive calcium channel blocking effects.
What to do
Monitor blood pressure and heart rate and consider a lower nifedipine dose when diltiazem is added. Reassess the need for dual calcium channel blocker therapy.
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 Nifedipine
Other interactions of Diltiazem
- Diltiazem + Flibanserin Contraindicated
- Diltiazem + Ivabradine Contraindicated
- Diltiazem + Lomitapide Contraindicated
- Diltiazem + Lonafarnib Contraindicated
- Acebutolol + Diltiazem Major
- Alfentanil + Diltiazem Major
Frequently asked questions
Can I take Diltiazem with Nifedipine?
MediHelp rates the interaction as moderate. Diltiazem and Nifedipine 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 raises nifedipine exposure, which can cause excessive vasodilation with hypotension, flushing, headache, peripheral edema and reflex tachycardia. Combining two calcium channel blockers also produces additive blood pressure lowering.
How serious is the interaction between Diltiazem and Nifedipine?
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 blood pressure and heart rate and consider a lower nifedipine dose when diltiazem is added. Reassess the need for dual calcium channel blocker therapy.
What other medicines interact with Nifedipine?
MediHelp also lists interactions of Nifedipine with, for example, Amifostine, Amlodipine-benazepril, Apalutamide. The full list is on the Nifedipine page.
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