Drug interactions
Butabarbital + Quinidine
Severity: Moderate
Butabarbital and Quinidine: 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
Barbiturates induce CYP3A4 and can substantially lower quinidine concentrations, reducing antiarrhythmic effect. Loss of efficacy may allow recurrent arrhythmia, and stopping the barbiturate can later cause quinidine levels to rise.
What this interaction means in plain words
Butabarbital and Quinidine 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
Butabarbital induces hepatic CYP3A4, increasing quinidine clearance.
What to do
Monitor quinidine levels and ECG, and adjust the quinidine dose when the barbiturate is started or stopped.
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 Quinidine
- Adagrasib + Quinidine Contraindicated
- Arsenic trioxide + Quinidine Contraindicated
- Artemether / lumefantrine + Quinidine Contraindicated
- Chloroquine + Quinidine Contraindicated
- Dofetilide + Quinidine Contraindicated
- Dronedarone + Quinidine Contraindicated
Frequently asked questions
Can I take Butabarbital with Quinidine?
MediHelp rates the interaction as moderate. Butabarbital and Quinidine 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. Barbiturates induce CYP3A4 and can substantially lower quinidine concentrations, reducing antiarrhythmic effect. Loss of efficacy may allow recurrent arrhythmia, and stopping the barbiturate can later cause quinidine levels to rise.
How serious is the interaction between Butabarbital and Quinidine?
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 quinidine levels and ECG, and adjust the quinidine dose when the barbiturate is started or stopped.
What other medicines interact with Quinidine?
MediHelp also lists interactions of Quinidine with, for example, Adagrasib, Arsenic trioxide, Artemether / lumefantrine. The full list is on the Quinidine page.
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