surface of the hind paw the same rats did not have dynamic allodynia of the hind paw in response to cotton swab stroking or spontaneous pain behavior a weight bearing preference between the hind paws pregabalin 10 and 30 mg kg po reduced static allodynia produced by prior acidic saline injections morphine 3 and 10 mg kg sc reduced static allodynia from prior acidic saline injections amitriptyline 6 mg kg po was without inhibitory effects on allodynia these results agree with previous published results for morphine sluka k a rohlwing j j bussey r a eikenberry s a wilken j m j pharmacol exp ther 2002 302 1146 50 although amitriptyline was without effect in this study it is often prescribed for fibromyalgia pain and clinical studies has shown it to be effective 5 6 it is possible that amitriptyline would be effective in this animal model with allodynia from repeated acidic saline injections if it were tested after repeated dosing for several days this possibility remains to be tested higer dosages of amitriptyline were not studied because tachycardia was observed at the 6 mg kg po dose and a 10 mg kg po dose was lethal in a fraction of rats that were injected static allodynia in the rat hind paw produced by prior repeated injections of acidic saline into the gastrocnemius muscle may provide a method.