Drug interactions
Diamorphine + Hydroxyzine
Severity: Major
Diamorphine and Hydroxyzine: 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
Diamorphine (heroin) is a strong opioid and hydroxyzine is a sedating antihistamine. Combined use increases sedation and the risk of respiratory depression, hypotension and impaired consciousness.
What this interaction means in plain words
Diamorphine and Hydroxyzine 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.
Why it happens
Additive central nervous system and respiratory depression from opioid agonism and central H1 antagonism.
What to do
Start with reduced doses and monitor sedation level and respiratory rate closely. Avoid in patients with compromised respiratory function unless monitored.
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 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 Diamorphine with Hydroxyzine?
MediHelp rates the interaction as major. Diamorphine and Hydroxyzine 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. Diamorphine (heroin) is a strong opioid and hydroxyzine is a sedating antihistamine. Combined use increases sedation and the risk of respiratory depression, hypotension and impaired consciousness.
How serious is the interaction between Diamorphine and Hydroxyzine?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Start with reduced doses and monitor sedation level and respiratory rate closely. Avoid in patients with compromised respiratory function unless monitored.
What other medicines interact with Hydroxyzine?
MediHelp also lists interactions of Hydroxyzine with, for example, Droperidol, Pimozide, Thioridazine. The full list is on the Hydroxyzine page.
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