Butorphanol and Fentanyl Interaction
Drug interaction information between Butorphanol and Fentanyl.
Butorphanol and Fentanyl have a documented minor interaction in FDA labeling.
FDA drug labeling documents a minor-severity interaction between Butorphanol and Fentanyl. This page displays the available source-record category and label text. The category is not an individual risk estimate or medication-combination direction.
How They Interact
Butorphanol can block the pain-relieving effects of fentanyl or cause sudden withdrawal symptoms because it works differently on the same brain receptors.
FDA Label Information
Examples: Butorphanol, nalbuphine, pentazocine, buprenorphine.
Butorphanol Also Interacts With
- Oxycodone moderate
- Acetaminophen/Oxycodone minor
- Buprenorphine (Pain) minor
- Codeine minor
- Hydromorphone minor
Fentanyl Also Interacts With
- Itraconazole moderate
- Tranylcypromine moderate
- Tramadol minor
- Cyclobenzaprine minor
- Ketoconazole minor
Frequently Asked Questions
What SPL severity band is on file for Butorphanol + Fentanyl?
Compiled FDA labeling labels this pair minor. That is a source-record field, not an individual medication-combination decision.
Which drug in this pair has the larger labeled-interaction portfolio?
Fentanyl has 28 labeled pairs on file vs Butorphanol's 11. In the minor band specifically: Butorphanol has 10 (also Acetaminophen/Oxycodone, Buprenorphine, Codeine, Hydromorphone); Fentanyl has 26 (also Tramadol, Cyclobenzaprine, Ketoconazole, Diazepam).
What mechanism field is on file for Butorphanol and Fentanyl?
Butorphanol can block the pain-relieving effects of fentanyl or cause sudden withdrawal symptoms because it works differently on the same brain receptors.
Fentanyl's labeled portfolio outnumbers Butorphanol
SPL source-record counts only. This page's band is minor · classes on file: Butorphanol (Opioid Agonist-Antagonist); Fentanyl (Opioid Analgesic).
0 major · 1 moderate · 10 minor · 11 total
- Other minor peers for Butorphanol
- Acetaminophen/Oxycodone
- Buprenorphine
- Codeine
- Hydromorphone
0 major · 2 moderate · 26 minor · 28 total
- Other minor peers for Fentanyl
- Tramadol
- Cyclobenzaprine
- Ketoconazole
- Diazepam
Sources: FDA Drug Labels (SPL) via openFDA (2026). This is for informational purposes only and is not medical advice. This registry does not provide individual medication-combination directions.
Read our methodology - how this data is sourced, computed, and verified.