Drug interactions
Ofloxacin + Quinidine
Severity: Major
Ofloxacin and Quinidine: major 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
Quinidine markedly prolongs the QT interval and ofloxacin adds a smaller further effect. The combination increases the risk of torsades de pointes and other ventricular arrhythmias.
What this interaction means in plain words
Ofloxacin and Quinidine can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for.
Ofloxacin belongs to Anti Bacterial; Quinidine belongs to Anti Parasitic.
Why it happens
Additive hERG potassium channel blockade causing delayed ventricular repolarization.
What to do
Avoid the combination and use an antibiotic without QT effects. If it cannot be avoided, monitor ECG and keep potassium and magnesium within normal range.
What to ask your pharmacist
- Does the benefit of taking both outweigh the risk in my case?
- Do I need any blood test, ECG or other check while on both?
- What early warning signs should I watch for, and what should I do if they appear?
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Other interactions of Ofloxacin
- Ofloxacin + Thioridazine Contraindicated
- Adagrasib + Ofloxacin Major
- Amiodarone + Ofloxacin Major
- Amisulpride + Ofloxacin Major
- Anagrelide + Ofloxacin Major
- Arsenic trioxide + Ofloxacin Major
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 Ofloxacin with Quinidine?
MediHelp rates the interaction as major. Ofloxacin and Quinidine can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for. Quinidine markedly prolongs the QT interval and ofloxacin adds a smaller further effect. The combination increases the risk of torsades de pointes and other ventricular arrhythmias.
How serious is the interaction between Ofloxacin and Quinidine?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid the combination and use an antibiotic without QT effects. If it cannot be avoided, monitor ECG and keep potassium and magnesium within normal range.
What other medicines interact with Ofloxacin?
MediHelp also lists interactions of Ofloxacin with, for example, Thioridazine, Adagrasib, Amiodarone. The full list is on the Ofloxacin page.
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