Drug interactions
Diltiazem + Lily of the valley
Severity: Moderate
Diltiazem and Lily of the valley: 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
Lily of the valley contains cardiac glycosides that slow AV conduction and can cause bradycardia and arrhythmias. Diltiazem also depresses sinoatrial and AV nodal conduction, so the combination may produce additive bradycardia or heart block, and toxicity from the plant can be more severe.
What this interaction means in plain words
Diltiazem and Lily of the valley 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.
Why it happens
Additive depression of AV nodal conduction from calcium channel blockade and cardiac glycoside effects of the plant constituents.
What to do
Avoid use of lily of the valley preparations with diltiazem. If exposure occurs, monitor ECG, heart rate and potassium and seek toxicology advice.
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
Frequently asked questions
Can I take Diltiazem with Lily of the valley?
MediHelp rates the interaction as moderate. Diltiazem and Lily of the valley 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. Lily of the valley contains cardiac glycosides that slow AV conduction and can cause bradycardia and arrhythmias. Diltiazem also depresses sinoatrial and AV nodal conduction, so the combination may produce additive bradycardia or heart block, and toxicity from the plant can be more severe.
How serious is the interaction between Diltiazem and Lily of the valley?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid use of lily of the valley preparations with diltiazem. If exposure occurs, monitor ECG, heart rate and potassium and seek toxicology advice.
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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