Drug interactions
Lily of the valley + Mexiletine
Severity: Minor
Lily of the valley and Mexiletine: minor 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 can cause arrhythmias and conduction block. Mexiletine is a class IB antiarrhythmic with its own proarrhythmic potential, so combined effects on conduction are possible but poorly documented.
What this interaction means in plain words
Lily of the valley and Mexiletine have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised.
Why it happens
Possible additive effects on cardiac conduction; the mechanism is not well established.
What to do
Avoid herbal lily of the valley products in patients on mexiletine, and obtain an ECG if palpitations or syncope occur.
What to ask your pharmacist
- Is there anything I should notice while taking both?
- Do I need to tell my doctor at the next visit?
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Other interactions of Mexiletine
- Fezolinetant + Mexiletine Contraindicated
- Mexiletine + Pimozide Contraindicated
- Alosetron + Mexiletine Major
- Amiodarone + Mexiletine Major
- Clozapine + Mexiletine Major
- Cobicistat + Mexiletine Major
Frequently asked questions
Can I take Lily of the valley with Mexiletine?
MediHelp rates the interaction as minor. Lily of the valley and Mexiletine have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised. Lily of the valley contains cardiac glycosides that can cause arrhythmias and conduction block. Mexiletine is a class IB antiarrhythmic with its own proarrhythmic potential, so combined effects on conduction are possible but poorly documented.
How serious is the interaction between Lily of the valley and Mexiletine?
MediHelp rates it minor, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid herbal lily of the valley products in patients on mexiletine, and obtain an ECG if palpitations or syncope occur.
What other medicines interact with Mexiletine?
MediHelp also lists interactions of Mexiletine with, for example, Fezolinetant, Pimozide, Alosetron. The full list is on the Mexiletine page.
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