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Drug interactions

Arsenic trioxide + Ofloxacin

Severity: Major

Arsenic trioxide and Ofloxacin: 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

Arsenic trioxide causes marked QT prolongation and torsades de pointes, and ofloxacin adds further risk. Together they may precipitate life-threatening ventricular arrhythmia.

What this interaction means in plain words

Arsenic trioxide and Ofloxacin 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.

Arsenic trioxide belongs to Oncology; Ofloxacin belongs to Anti Bacterial.

Evidence level: Moderate

Why it happens

Additive QT prolongation; arsenic trioxide alters cardiac ion currents and ofloxacin blocks hERG potassium channels.

What to do

Avoid the combination and choose a non-QT-prolonging antibiotic. If unavoidable, 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?

Bring a full list of your medicines, including over-the-counter products, supplements and herbal remedies, to every pharmacy visit.

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Frequently asked questions

Can I take Arsenic trioxide with Ofloxacin?

MediHelp rates the interaction as major. Arsenic trioxide and Ofloxacin 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. Arsenic trioxide causes marked QT prolongation and torsades de pointes, and ofloxacin adds further risk. Together they may precipitate life-threatening ventricular arrhythmia.

How serious is the interaction between Arsenic trioxide and Ofloxacin?

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 choose a non-QT-prolonging antibiotic. If unavoidable, 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.

Full monographs, dosing and an interaction checker in the MediHelp app

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