Drug interactions
Quinidine + Sofosbuvir / velpatasvir
Severity: Moderate
Quinidine and Sofosbuvir / velpatasvir: 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
Velpatasvir inhibits P-glycoprotein and other transporters, and quinidine is a P-gp substrate, so quinidine exposure could increase. The magnitude is uncertain, but quinidine has a narrow therapeutic index.
What this interaction means in plain words
Quinidine and Sofosbuvir / velpatasvir 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
Velpatasvir inhibits P-glycoprotein (and possibly weakly CYP3A4), which may reduce quinidine clearance.
What to do
Monitor ECG and QTc and watch for signs of quinidine toxicity during coadministration. Check quinidine levels if possible and reduce the dose if concentrations are elevated.
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 Quinidine with Sofosbuvir / velpatasvir?
MediHelp rates the interaction as moderate. Quinidine and Sofosbuvir / velpatasvir 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. Velpatasvir inhibits P-glycoprotein and other transporters, and quinidine is a P-gp substrate, so quinidine exposure could increase. The magnitude is uncertain, but quinidine has a narrow therapeutic index.
How serious is the interaction between Quinidine and Sofosbuvir / velpatasvir?
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 and QTc and watch for signs of quinidine toxicity during coadministration. Check quinidine levels if possible and reduce the dose if concentrations are elevated.
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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