Table 1.
Phase 1: Baseline | Phase 2: Morphine dependence induction | Phase 3: Spontaneous withdrawal | Phase 4: Precipitated withdrawal | |
---|---|---|---|---|
# of sessions | ~5 | 8 | ~6a | 4 |
Pre-session injection (4 h) | SAL | MOR or SAL | SAL | MOR or SAL |
Pre-session injection (5 min) | SAL | SAL | SAL | NAL |
Sessions were conducted once daily except during the first day of phase 3, during which sessions were conducted twice (i.e., 24 and 28 h following the last MOR injection of Phase 2)
MOR = morphine (10 mg/kg); NAL = naloxone (1 mg/kg); SAL = saline