The effects of combination of two lornoxicam doses and nitroglycerine on acute pain in rats

Abstract

Transdermal nitroglycerine can improve analgesic effects when used with other analgesics. The aim of the study was to investigate the additive effects of nitroglycerine combined with lornoxicam for acute pain in rats. Thirty-nine Wistar male rats were divided into five groups; Group SF (n=8, saline), Group L-1 (n=8, lornoxicam 1.3 mg/kg), Group L-2 (n=8, lornoxicam 2.6 mg/kg), Group LNO (n=8, nitroglycerine and lornoxicam, 1 mg/kg + 1.3 mg/kg), and Group LNO-2 (n=8, nitroglycerine and lornoxicam, 1 mg/ kg + 2.6 mg/kg). Tail flick and hot plate tests were measured in all groups before the intraperitoneal injections of drug and 30, 60 and 90 minutes after the injections. Cut-off time was 20 s and 60 s in tail-flick and hot-plate tests. Although there were significant differences between the groups according to hot-plate test at the 30th, 60th and 90th minutes (p<0.05), there was no difference between the groups with tail flick test. The most increasing of latency response in hot-plate assays was seen in Group LNO-1 compared to other groups at the 30th minute (p<0.05). The latency response increased significantly in Group L-1, L-2, LNO-1 and LNO-2 compared with saline group at the 60th and 90th minutes (p <0.05). There were significant differences in latency responses in Group L-1 and Group LNO-1 compared to Group L-2 and Group LNO-2 at the 60th and 90th minutes. In conclusion, 1.3 mg/kg dose of lornoksicam with the use of nitrogliserine provided early and efficient analgesia, but the increasing dose of lornoksicam did not maintain better analgesia.