Drug interactions
Quinine + Verapamil
Severity: Moderate
Quinine 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 modestly raise quinine exposure through CYP3A4 and P-glycoprotein inhibition, while quinine may reduce renal elimination of verapamil. Both drugs can affect cardiac conduction and QT interval, so additive effects are possible in susceptible patients.
What this interaction means in plain words
Quinine 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.
Quinine belongs to Anti Parasitic; Verapamil belongs to Cardiovascular.
Why it happens
Verapamil inhibits CYP3A4 and P-glycoprotein, and both drugs have additive effects on cardiac conduction and repolarization.
What to do
Monitor ECG for PR and QT prolongation and watch for hypotension or bradycardia when the two are combined. Reduce doses or choose an alternative if conduction abnormalities develop.
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 Quinine
- Arsenic trioxide + Quinine Contraindicated
- Dofetilide + Quinine Contraindicated
- Dronedarone + Quinine Contraindicated
- Ibutilide + Quinine Contraindicated
- Mefloquine + Quinine Contraindicated
- Nilotinib + Quinine Contraindicated
Other interactions of Verapamil
- Dofetilide + Verapamil Contraindicated
- Flibanserin + Verapamil Contraindicated
- Lomitapide + Verapamil Contraindicated
- Lonafarnib + Verapamil Contraindicated
- Pimozide + Verapamil Contraindicated
- Acebutolol + Verapamil Major
Frequently asked questions
Can I take Quinine with Verapamil?
MediHelp rates the interaction as moderate. Quinine 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 modestly raise quinine exposure through CYP3A4 and P-glycoprotein inhibition, while quinine may reduce renal elimination of verapamil. Both drugs can affect cardiac conduction and QT interval, so additive effects are possible in susceptible patients.
How serious is the interaction between Quinine 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 ECG for PR and QT prolongation and watch for hypotension or bradycardia when the two are combined. Reduce doses or choose an alternative if conduction abnormalities develop.
What other medicines interact with Quinine?
MediHelp also lists interactions of Quinine with, for example, Arsenic trioxide, Dofetilide, Dronedarone. The full list is on the Quinine page.
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