Drug interactions
Quinidine + Secobarbital
Severity: Moderate
Quinidine and Secobarbital: 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 hepatic CYP3A4 and can substantially lower quinidine concentrations. This may lead to loss of antiarrhythmic effect or treatment failure. Quinidine levels can rebound if the barbiturate is stopped.
What this interaction means in plain words
Quinidine and Secobarbital 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.
Quinidine belongs to Anti Parasitic; Secobarbital belongs to Central Nervous System.
Why it happens
Barbiturate enzyme induction (CYP3A4) increases quinidine clearance.
What to do
Monitor quinidine serum levels and the ECG, and increase the dose if needed. Reduce the dose when the barbiturate is withdrawn.
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
Other interactions of Secobarbital
- Calcium / magnesium / potassium / sodium oxybates + Secobarbital Contraindicated
- Doravirine + Secobarbital Contraindicated
- Elbasvir / grazoprevir + Secobarbital Contraindicated
- Elvitegravir / cobicistat / emtricitabine / tenofovir df + Secobarbital Contraindicated
- Isavuconazonium + Secobarbital Contraindicated
- Lonafarnib + Secobarbital Contraindicated
Frequently asked questions
Can I take Quinidine with Secobarbital?
MediHelp rates the interaction as moderate. Quinidine and Secobarbital 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 hepatic CYP3A4 and can substantially lower quinidine concentrations. This may lead to loss of antiarrhythmic effect or treatment failure. Quinidine levels can rebound if the barbiturate is stopped.
How serious is the interaction between Quinidine and Secobarbital?
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 serum levels and the ECG, and increase the dose if needed. Reduce the dose when the barbiturate is withdrawn.
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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