Drug interactions
Guselkumab + Quinidine
Severity: Minor
Guselkumab and Quinidine: minor 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
Chronic inflammation can suppress CYP450 enzyme expression, and effective IL-23 blockade may reverse this suppression. Quinidine has a narrow therapeutic index, so any change in its metabolism could alter its levels. The clinical effect is expected to be small and is mostly theoretical.
What this interaction means in plain words
Guselkumab and Quinidine have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised.
Guselkumab belongs to Miscellaneous; Quinidine belongs to Anti Parasitic.
Why it happens
Cytokine normalization after IL-23 inhibition may restore CYP3A4 activity and so modestly lower quinidine exposure.
What to do
When guselkumab is started or stopped in a patient taking quinidine, check the ECG and quinidine concentration if clinically indicated. Adjust the quinidine dose only if the response or serum level changes.
What to ask your pharmacist
- Is there anything I should notice while taking both?
- Do I need to tell my doctor at the next visit?
Pro+ members
Unlock the full page
Create an account and start a Pro+ trial to unlock the full management advice for Guselkumab and Quinidine, the additional notes, the evidence detail and the whole-prescription interaction checker.
- Full clinical management advice
- Additional notes
- Evidence detail
- Interaction checker for a whole prescription
Try Pro+ free for 7 days on the web. No card needed.
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 Guselkumab
- Adenovirus types 4 and 7 live + Guselkumab Major
- Bcg vaccine live + Guselkumab Major
- Guselkumab + Influenza virus vaccine quadrivalent intranasal Major
- Guselkumab + Measles mumps and rubella vaccine live Major
- Guselkumab + Measles mumps rubella and varicella vaccine live Major
- Guselkumab + Measles vaccine Major
Frequently asked questions
Can I take Guselkumab with Quinidine?
MediHelp rates the interaction as minor. Guselkumab and Quinidine have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised. Chronic inflammation can suppress CYP450 enzyme expression, and effective IL-23 blockade may reverse this suppression. Quinidine has a narrow therapeutic index, so any change in its metabolism could alter its levels. The clinical effect is expected to be small and is mostly theoretical.
How serious is the interaction between Guselkumab and Quinidine?
MediHelp rates it minor, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: When guselkumab is started or stopped in a patient taking quinidine, check the ECG and quinidine concentration if clinically indicated. Adjust the quinidine dose only if the response or serum level changes.
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.
Full monographs, dosing and an interaction checker in the MediHelp app
Open the complete reference, check multi-drug interactions and use dosing tools in the MediHelp app.
