Drug interactions
Hydroxyzine + Levofloxacin
Severity: Major
Hydroxyzine and Levofloxacin: major interaction.
Last updated Sources: UK SmPC
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
Hydroxyzine can prolong the QT interval and has been linked to torsades de pointes, and levofloxacin shares this risk. Using them together increases arrhythmia risk, especially in older adults or those with cardiac disease.
What this interaction means in plain words
Hydroxyzine and Levofloxacin 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.
Hydroxyzine belongs to Respiratory; Levofloxacin belongs to Anti Bacterial.
Why it happens
Additive hERG channel blockade causing QT prolongation.
What to do
Avoid the combination where possible by choosing a non-QT-prolonging antihistamine or antibiotic. If both are needed, use the lowest hydroxyzine dose and monitor ECG and electrolytes.
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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References
Other interactions of Levofloxacin
- Dronedarone + Levofloxacin Contraindicated
- Ibutilide + Levofloxacin Contraindicated
- Levofloxacin + Thioridazine Contraindicated
- Levofloxacin + Vandetanib Contraindicated
- Levofloxacin + Ziprasidone Contraindicated
- Adagrasib + Levofloxacin Major
Other interactions of Hydroxyzine
- Droperidol + Hydroxyzine Contraindicated
- Hydroxyzine + Pimozide Contraindicated
- Hydroxyzine + Thioridazine Contraindicated
- Hydroxyzine + Vandetanib Contraindicated
- Alfentanil + Hydroxyzine Major
- Amiodarone + Hydroxyzine Major
Frequently asked questions
Can I take Hydroxyzine with Levofloxacin?
MediHelp rates the interaction as major. Hydroxyzine and Levofloxacin 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. Hydroxyzine can prolong the QT interval and has been linked to torsades de pointes, and levofloxacin shares this risk. Using them together increases arrhythmia risk, especially in older adults or those with cardiac disease.
How serious is the interaction between Hydroxyzine and Levofloxacin?
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 where possible by choosing a non-QT-prolonging antihistamine or antibiotic. If both are needed, use the lowest hydroxyzine dose and monitor ECG and electrolytes.
What other medicines interact with Levofloxacin?
MediHelp also lists interactions of Levofloxacin with, for example, Dronedarone, Ibutilide, Thioridazine. The full list is on the Levofloxacin page.
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