Drug interactions
Clozapine + Verapamil
Severity: Moderate
Clozapine and Verapamil: 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
Verapamil may increase clozapine concentrations, increasing the risk of sedation, hypotension, seizures and cardiac effects. Both drugs can affect cardiac conduction and blood pressure.
What this interaction means in plain words
Clozapine and Verapamil 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.
Clozapine belongs to Central Nervous System; Verapamil belongs to Cardiovascular.
Why it happens
Verapamil inhibits CYP3A4 and possibly CYP1A2, reducing clozapine metabolism, with additive hypotensive effects.
What to do
Monitor blood pressure, ECG and sedation, and consider checking clozapine levels or reducing the dose if adverse effects arise.
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 Verapamil
- Dofetilide + Verapamil Contraindicated
- Flibanserin + Verapamil Contraindicated
- Lomitapide + Verapamil Contraindicated
- Lonafarnib + Verapamil Contraindicated
- Pimozide + Verapamil Contraindicated
- Acebutolol + Verapamil Major
Other interactions of Clozapine
- Clozapine + Deferiprone Contraindicated
- Clozapine + Irinotecan Contraindicated
- Clozapine + Pimozide Contraindicated
- Clozapine + Thioridazine Contraindicated
- Acalabrutinib + Clozapine Major
- Adagrasib + Clozapine Major
Frequently asked questions
Can I take Clozapine with Verapamil?
MediHelp rates the interaction as moderate. Clozapine and Verapamil 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. Verapamil may increase clozapine concentrations, increasing the risk of sedation, hypotension, seizures and cardiac effects. Both drugs can affect cardiac conduction and blood pressure.
How serious is the interaction between Clozapine and Verapamil?
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, ECG and sedation, and consider checking clozapine levels or reducing the dose if adverse effects arise.
What other medicines interact with Verapamil?
MediHelp also lists interactions of Verapamil with, for example, Dofetilide, Flibanserin, Lomitapide. The full list is on the Verapamil page.
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