Drug interactions
Butorphanol + Clozapine
Severity: Major
Butorphanol and Clozapine: 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
Both drugs depress the central nervous system, so combining them can produce marked drowsiness, dizziness and slowed psychomotor performance. Clozapine can also cause orthostatic hypotension and, rarely, respiratory depression, and an opioid may add to these effects.
What this interaction means in plain words
Butorphanol and Clozapine 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; Clozapine belongs to Central Nervous System.
Why it happens
Additive CNS depression from opioid agonist-antagonist activity and clozapine's antihistaminic, anticholinergic and antiadrenergic effects.
What to do
Start butorphanol at a reduced dose and titrate slowly, monitoring sedation, blood pressure and respiratory rate. Warn patients against driving or operating machinery.
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 Butorphanol
- Butorphanol + Olanzapine / samidorphan Contraindicated
- Butorphanol + Sodium oxybate Contraindicated
- Alfentanil + Butorphanol Major
- Alprazolam + Butorphanol Major
- Alvimopan + Butorphanol Major
- Amobarbital + Butorphanol Major
Other interactions of Clozapine
- Clozapine + Deferiprone Contraindicated
- Clozapine + Irinotecan Contraindicated
- Clozapine + Pimozide Contraindicated
- Clozapine + Thioridazine Contraindicated
- Acalabrutinib + Clozapine Major
- Adagrasib + Clozapine Major
Frequently asked questions
Can I take Butorphanol with Clozapine?
MediHelp rates the interaction as major. Butorphanol and Clozapine 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 combining them can produce marked drowsiness, dizziness and slowed psychomotor performance. Clozapine can also cause orthostatic hypotension and, rarely, respiratory depression, and an opioid may add to these effects.
How serious is the interaction between Butorphanol and Clozapine?
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 butorphanol at a reduced dose and titrate slowly, monitoring sedation, blood pressure and respiratory rate. Warn patients against driving or operating machinery.
What other medicines interact with Butorphanol?
MediHelp also lists interactions of Butorphanol with, for example, Olanzapine / samidorphan, Sodium oxybate, Alfentanil. The full list is on the Butorphanol page.
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