Table 1.

Comparison of thermal antinociceptive effects of hydromorphone (0.1 mg/kg) given by the IV, IM and SC routes

Route of administration	Significant increase in TT (min)	Duration of increase in TT (min)	Peak mean TT (°C)	Time of peak TT (min)
IV *	15–450	435	55.0	45
IV †	5–200	195	54.9	20
IM ‡	15–345	330	49.0	30
SC §	15, 60–210	150	52.6	105

^*Data from Wagner et al ⁶

^†Data from Wagner and Robertson ⁵

^‡Data from Lascelles and Robertson ⁴

^§Data from current study.