Drug interactions
Metaproterenol + Pimozide
Severity: Moderate
Metaproterenol and Pimozide: 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
Metaproterenol is a beta-agonist that can cause tachycardia, hypokalemia and QT prolongation at higher doses. Because pimozide prolongs the QT interval, the combination may raise the risk of ventricular arrhythmia.
What this interaction means in plain words
Metaproterenol and Pimozide 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 proarrhythmic effects, with beta-agonist-induced hypokalemia potentiating pimozide-related QT prolongation.
What to do
Monitor potassium and ECG in patients with cardiac risk factors or high beta-agonist use. Keep metaproterenol at the lowest effective dose.
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 Pimozide
- Adagrasib + Pimozide Contraindicated
- Amiodarone + Pimozide Contraindicated
- Amisulpride + Pimozide Contraindicated
- Amitriptyline + Pimozide Contraindicated
- Amoxapine + Pimozide Contraindicated
- Anagrelide + Pimozide Contraindicated
Frequently asked questions
Can I take Metaproterenol with Pimozide?
MediHelp rates the interaction as moderate. Metaproterenol and Pimozide 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. Metaproterenol is a beta-agonist that can cause tachycardia, hypokalemia and QT prolongation at higher doses. Because pimozide prolongs the QT interval, the combination may raise the risk of ventricular arrhythmia.
How serious is the interaction between Metaproterenol and Pimozide?
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 potassium and ECG in patients with cardiac risk factors or high beta-agonist use. Keep metaproterenol at the lowest effective dose.
What other medicines interact with Pimozide?
MediHelp also lists interactions of Pimozide with, for example, Adagrasib, Amiodarone, Amisulpride. The full list is on the Pimozide page.
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