A comparison between analgesic effects of ranitidine and morphine in mice

Objectives: Long-term consumption of many drugs followed by reduction of their effectiveness has necessitated performing research on new analgesics.Thus, the present study was conducted to evaluate the analgesic effects of ranitidine and morphine in mice using writhing and hot plate tests.Materials Methods: In this experimental study, 28 male mice were divided into 4 equal groups. The groups included the control, three experimental groups receiving 200mg/kg ranitidine, 2mg/kg morphine and200 mg/kg ranitidine+ 2 mg/kg morphine. In order to measure pain, the two acceptable tests, writhing and hot plate tests, were applied. Pain scores were measured at 0, 15, 30, 4560 min after administration of algogenic stimulus.Results Conclusion: In hot plate test it was not found significance effect between ranitidine and control groups butin wrighting test, ranitidine at this dose significantly reduced the number and time of wrightes in the mice and it was comparable to morphine (P 0.05). It seems that ranitidine in weighting test have analgesic effects which indicate chronic pain inhibition of ranitidine