Drug interactions
Butorphanol + Promethazine
Severity: Major
Butorphanol and Promethazine: major interaction.
Last updated Sources: US FDA label
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
Promethazine and the opioid agonist-antagonist butorphanol both depress the CNS. Together they can cause profound sedation, respiratory depression and hypotension.
What this interaction means in plain words
Butorphanol 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.
Butorphanol belongs to Musculoskeletal; Promethazine belongs to Respiratory.
Why it happens
Additive central nervous system and respiratory depression.
What to do
Start with reduced doses of each drug and monitor sedation level and respiratory rate. Avoid in patients with compromised respiration.
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 Promethazine
- Cabergoline + Promethazine Contraindicated
- Dopamine + Promethazine Contraindicated
- Ibutilide + Promethazine Contraindicated
- Pimozide + Promethazine Contraindicated
- Promethazine + Thioridazine Contraindicated
- Alfentanil + Promethazine Major
Other interactions of Butorphanol
- Butorphanol + Olanzapine / samidorphan Contraindicated
- Butorphanol + Sodium oxybate Contraindicated
- Alfentanil + Butorphanol Major
- Alprazolam + Butorphanol Major
- Alvimopan + Butorphanol Major
- Amobarbital + Butorphanol Major
Frequently asked questions
Can I take Butorphanol with Promethazine?
MediHelp rates the interaction as major. Butorphanol 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. Promethazine and the opioid agonist-antagonist butorphanol both depress the CNS. Together they can cause profound sedation, respiratory depression and hypotension.
How serious is the interaction between Butorphanol 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: Start with reduced doses of each drug and monitor sedation level and respiratory rate. Avoid in patients with compromised respiration.
What other medicines interact with Promethazine?
MediHelp also lists interactions of Promethazine with, for example, Cabergoline, Dopamine, Ibutilide. The full list is on the Promethazine page.
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