Drug interactions
Lily of the valley + Metolazone
Severity: Major
Lily of the valley and Metolazone: major 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, and metolazone-induced hypokalemia and hypomagnesemia increase sensitivity to glycoside toxicity. This can lead to serious arrhythmias, nausea and visual disturbances.
What this interaction means in plain words
Lily of the valley and Metolazone can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for.
Why it happens
Diuretic-induced potassium and magnesium depletion sensitises the myocardium to the digoxin-like effects of the plant's cardiac glycosides.
What to do
Avoid lily of the valley products with metolazone. If exposure has occurred or is suspected, check potassium, magnesium and ECG and correct electrolytes promptly.
What to ask your pharmacist
- Does the benefit of taking both outweigh the risk in my case?
- Do I need any blood test, ECG or other check while on both?
- What early warning signs should I watch for, and what should I do if they appear?
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Other interactions of Metolazone
Frequently asked questions
Can I take Lily of the valley with Metolazone?
MediHelp rates the interaction as major. Lily of the valley and Metolazone can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for. Lily of the valley contains cardiac glycosides, and metolazone-induced hypokalemia and hypomagnesemia increase sensitivity to glycoside toxicity. This can lead to serious arrhythmias, nausea and visual disturbances.
How serious is the interaction between Lily of the valley and Metolazone?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid lily of the valley products with metolazone. If exposure has occurred or is suspected, check potassium, magnesium and ECG and correct electrolytes promptly.
What other medicines interact with Metolazone?
MediHelp also lists interactions of Metolazone with, for example, Amifostine, Amlodipine-hydrochlorothiazide-valsartan, Amlodipine-olmesartan-hydrochlorothiazide. The full list is on the Metolazone page.
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