Drug interactions
Hydroxyzine + Methadone
Severity: Major
Hydroxyzine and Methadone: 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
Both drugs can prolong the QT interval, so combined use raises the risk of torsades de pointes. Hydroxyzine also adds sedative effects to the CNS and respiratory depression from methadone.
What this interaction means in plain words
Hydroxyzine and Methadone 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; Methadone belongs to Musculoskeletal.
Why it happens
Additive QTc prolongation through hERG channel blockade plus additive CNS depression.
What to do
Obtain a baseline ECG and monitor QTc, and correct potassium and magnesium disturbances. Use the lowest effective hydroxyzine dose or choose an alternative antihistamine, and warn the patient about sedation.
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 Methadone
- Alvimopan + Methadone Contraindicated
- Calcium / magnesium / potassium / sodium oxybates + Methadone Contraindicated
- Droperidol + Methadone Contraindicated
- Ibutilide + Methadone Contraindicated
- Isocarboxazid + Methadone Contraindicated
- Lefamulin + Methadone Contraindicated
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 Methadone?
MediHelp rates the interaction as major. Hydroxyzine and Methadone 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. Both drugs can prolong the QT interval, so combined use raises the risk of torsades de pointes. Hydroxyzine also adds sedative effects to the CNS and respiratory depression from methadone.
How serious is the interaction between Hydroxyzine and Methadone?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Obtain a baseline ECG and monitor QTc, and correct potassium and magnesium disturbances. Use the lowest effective hydroxyzine dose or choose an alternative antihistamine, and warn the patient about sedation.
What other medicines interact with Methadone?
MediHelp also lists interactions of Methadone with, for example, Alvimopan, Calcium / magnesium / potassium / sodium oxybates, Droperidol. The full list is on the Methadone page.
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