Drug interactions
Levofloxacin + Thioridazine
Severity: Contraindicated
Levofloxacin and Thioridazine: contraindicated 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
Thioridazine is strongly associated with dose-related QT prolongation and torsades de pointes, and its labeling contraindicates use with other QT-prolonging drugs. Adding levofloxacin compounds the arrhythmia risk.
What this interaction means in plain words
Levofloxacin and Thioridazine are not normally used together. Taking them at the same time is expected to cause harm or make one of them unsafe, so a different medicine is usually chosen for one of the two.
Levofloxacin belongs to Anti Bacterial; Thioridazine belongs to Central Nervous System.
Why it happens
Additive blockade of cardiac potassium channels causing marked delay in ventricular repolarization.
What to do
Do not co-administer; select an antibiotic without QT liability. If a fluoroquinolone is unavoidable, thioridazine should be held under specialist guidance.
What to ask your pharmacist
- Is there an alternative to one of these two medicines for me?
- If both are essential, who is monitoring me and how often?
- Which symptoms mean I should stop and seek help straight away?
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Other interactions of Levofloxacin
- Dronedarone + Levofloxacin Contraindicated
- Ibutilide + Levofloxacin Contraindicated
- Levofloxacin + Vandetanib Contraindicated
- Levofloxacin + Ziprasidone Contraindicated
- Adagrasib + Levofloxacin Major
- Amiodarone + Levofloxacin Major
Other interactions of Thioridazine
- Abiraterone + Thioridazine Contraindicated
- Adagrasib + Thioridazine Contraindicated
- Amiodarone + Thioridazine Contraindicated
- Amisulpride + Thioridazine Contraindicated
- Amitriptyline + Thioridazine Contraindicated
- Amoxapine + Thioridazine Contraindicated
Frequently asked questions
Can I take Levofloxacin with Thioridazine?
MediHelp rates the interaction as contraindicated. Levofloxacin and Thioridazine are not normally used together. Taking them at the same time is expected to cause harm or make one of them unsafe, so a different medicine is usually chosen for one of the two. Thioridazine is strongly associated with dose-related QT prolongation and torsades de pointes, and its labeling contraindicates use with other QT-prolonging drugs. Adding levofloxacin compounds the arrhythmia risk.
How serious is the interaction between Levofloxacin and Thioridazine?
MediHelp rates it contraindicated, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Do not co-administer; select an antibiotic without QT liability. If a fluoroquinolone is unavoidable, thioridazine should be held under specialist guidance.
What other medicines interact with Levofloxacin?
MediHelp also lists interactions of Levofloxacin with, for example, Dronedarone, Ibutilide, Vandetanib. The full list is on the Levofloxacin page.
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