Drug interactions
Hydromorphone + Thioridazine
Severity: Major
Hydromorphone and Thioridazine: 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 depress the central nervous system, so combined use can cause marked drowsiness, impaired psychomotor function and respiratory depression. Thioridazine also carries a risk of QT prolongation and hypotension, which may add to opioid-related hemodynamic effects.
What this interaction means in plain words
Hydromorphone and Thioridazine 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.
Hydromorphone belongs to Musculoskeletal; Thioridazine belongs to Central Nervous System.
Why it happens
Additive CNS depressant effects; hydromorphone is mainly glucuronidated, so the CYP2D6 inhibition by thioridazine is unlikely to be clinically relevant.
What to do
Start with the lowest effective hydromorphone dose and monitor sedation, respiratory rate and blood pressure. Avoid in patients with QT risk factors or when other CNS depressants are present.
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 Hydromorphone
- Alvimopan + Hydromorphone Contraindicated
- Bupropion-naltrexone + Hydromorphone Contraindicated
- Hydromorphone + Isocarboxazid Contraindicated
- Hydromorphone + Olanzapine / samidorphan Contraindicated
- Hydromorphone + Phenelzine Contraindicated
- Hydromorphone + Tranylcypromine Contraindicated
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 Hydromorphone with Thioridazine?
MediHelp rates the interaction as major. Hydromorphone and Thioridazine 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 depress the central nervous system, so combined use can cause marked drowsiness, impaired psychomotor function and respiratory depression. Thioridazine also carries a risk of QT prolongation and hypotension, which may add to opioid-related hemodynamic effects.
How serious is the interaction between Hydromorphone and Thioridazine?
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 the lowest effective hydromorphone dose and monitor sedation, respiratory rate and blood pressure. Avoid in patients with QT risk factors or when other CNS depressants are present.
What other medicines interact with Hydromorphone?
MediHelp also lists interactions of Hydromorphone with, for example, Alvimopan, Bupropion-naltrexone, Isocarboxazid. The full list is on the Hydromorphone page.
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