Summary
Butorphanol is marketed as Stadol (human formulation, now discontinued as brand name) and Torbugesic (veterinary). As a potent κ-opioid receptor agonist with partial agonist/antagonist activity at the μ-receptor, it produces analgesia with less respiratory depression than morphine but a high incidence of dysphoria, vertigo, and hallucinatory experiences. Recreational reports describe darkened or tunnel vision, mild warmth, dissociative or salvia-like headspace, and amnestic episodes at higher doses. Can precipitate withdrawal in users dependent on strong μ-agonists (morphine, methadone, fentanyl). Concomitant CNS depressants markedly increase risk of respiratory depression.
Dose Information
Light
Common
Strong
Heavy
Onset, Duration & After-effects
| ROA | Onset | Comeup | Peak | Offset | After Effects |
|---|---|---|---|---|---|
| Intranasal | 10-15 min | 15-30 min | 30-90 min | 1-2 hrs | 2-6 hrs |
| Intravenous | 1-3 min | 5-15 min | 30-90 min | 1-2 hrs | 2-6 hrs |
| Intramuscular | 10-30 min | 20-40 min | 30-90 min | 1-2 hrs | 2-6 hrs |
| Oral | 30-60 min | 45-90 min | 1-2 hrs | 1-2 hrs | 2-6 hrs |
Tolerance
Build-up
develops within days of regular use; analgesic tolerance faster than respiratory depression tolerance
Reset
7–14 days for partial reset; full reset may take weeks — tolerance loss greatly increases overdose risk
Effects
Positive
- Analgesia
- Physical euphoria
Negative
- Vertigo
- Nausea
- Increased perspiration
- Abnormal heartbeat
- Dry Mouth
- Sedation
- Itchiness
- Changes in blood pressure
Positive
- Euphoria
- Cognitive euphoria
- Mood lift
Negative
- Anxiety
- Dizziness
- Depersonalization
- Derealization
- Memory suppression
- Constipation
- Compulsive redosing
Positive
Negative
- Cognitive dysphoria
- Visual suppression
- Appetite suppression
- Double vision
- Decreased Libido
- Appetite Suppression
- Decreased libido
- Dulled perception
- Internal hallucination
- Internal hallucinations