Drug interactions
Opium tincture + Promethazine
Severity: Major
Opium tincture and Promethazine: 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
Opium tincture contains morphine and other opioid alkaloids that depress the CNS and respiration. Adding promethazine increases sedation and the risk of respiratory depression and hypotension.
What this interaction means in plain words
Opium tincture and Promethazine 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 CNS and respiratory depression from opioid agonism and H1 antihistamine sedation.
What to do
Use the lowest effective doses and monitor sedation and respiratory rate, particularly in older, frail or opioid-naive patients. Avoid other CNS depressants and alcohol.
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 Promethazine
- Ibutilide + Promethazine Contraindicated
- Pimozide + Promethazine Contraindicated
- Promethazine + Thioridazine Contraindicated
- Alfentanil + Promethazine Major
- Amiodarone + Promethazine Major
- Amisulpride + Promethazine Major
Frequently asked questions
Can I take Opium tincture with Promethazine?
MediHelp rates the interaction as major. Opium tincture and Promethazine 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. Opium tincture contains morphine and other opioid alkaloids that depress the CNS and respiration. Adding promethazine increases sedation and the risk of respiratory depression and hypotension.
How serious is the interaction between Opium tincture and Promethazine?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Use the lowest effective doses and monitor sedation and respiratory rate, particularly in older, frail or opioid-naive patients. Avoid other CNS depressants and alcohol.
What other medicines interact with Promethazine?
MediHelp also lists interactions of Promethazine with, for example, Ibutilide, Pimozide, Thioridazine. The full list is on the Promethazine page.
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