Intrathecal/systemic morphine synergy in mice
Morphine intrathecal ED50 is 305 ng (153, 501). Morphine given intrathecally at a dose less than 10% of its intrathecal ED50 shifted the systemic analgesic dose-response curve over 6-fold. From Kolesnikov et al. (1996b).
| Systemic Morphine ED50 | Systemic Shift | |
|---|---|---|
| mg/kg s.c. | -fold | |
| Systemic alone | 3.1 (1.6, 4.4) | |
| + 25 ng of Intrathecal morphine | 0.5 (0.4, 0.8) | >6 |