Topical ketorolac has no antinociceptive or anti-inflammatory effect in thermal injury

This study investigated the antinociceptive and anti-inflammatory effect of a topical non-steroidal anti-inflammatory drug in human thermal injury. Twelve healthy unmedicated volunteers had identical burn injuries produced on the medial side of both calves with a 49 degrees C 15 x 25 mm thermode. Ketorolac gel or placebo were randomly applied on the right or left calf 1.5 h before burn injury, immediately after burn injury and 6 and 12 h later in a double-blind trial where every subject served as his own control. Heat pain detection thresholds (HPDT), head pain tolerance (HPT), mechanical pain detection thresholds (MPDT) and the intensity of burn-induced erythema (erythema index, EI) were assessed in the area of the thermal injury, and areas of hyperalgesia to pin prick were determined outside the injury before and 3, 6 and 24 h after the burn injury. Burn injury led to a decrease in HPDT, HPT and MPDT, an increase in EI and development of mechanical hyperalgesia (P < 0.05). Ketorolac gel had no effect on any of the nociceptive or inflammatory variables studies (P > 0.2).