ED50 (mg/kg) obtained by one group using several tests on two species of animal and several analgesic substances
| Mouse | Rat | ||||
|---|---|---|---|---|---|
| Tail-Flick | Hot-Plate | Writhing | Writhing | Formalin | |
| Morphine (s.c.) | 3.3 | 3.7 | 0.2 | 0.3 | 0.2 |
| Meperidine (s.c.) | 10.3 | 10.6 | 2.3 | ||
| Codeine (s.c.) | 28.9 | 33.6 | 2.4 | ||
| Pentazocine (s.c.) | >50 | 16.9 | 0.8 | 0.7 | 2.4 |
| Aspirin (p.o.) | >200 | >200 | 47.8 | 67.5 | >150 |
| Paracetamol (p.o.) | 52 | 118 | >300 | ||
| Zomepirac (p.o.) | >100 | >50 | 2 | ||
The ED50 values that approach the doses used in man are in boldface type. All the others are much higher (adapted from Hammond, 1989).