Correlation between the analgesic and antipyretic effects of aspirin and salicylic acid concentration in rabbits

Abstract

In order to clarify the correlation between the analgesic and antipyretic effects of aspirin and salicylic acid concentration, a jaw-opening reflex test and pyrogenic test were performed under the presence of aspirin, and the corresponding plasma concentration of salicylic acid was measured using rabbits. The analgesic effect of aspirin determined by jaw-opening reflex was significantly dependent on plasma level. The antipyretic effect of aspirin obtained by the pyrogenic test was also significantly dependent on plasma level. A closer correlation was demonstrated between the integral antipyretic effect and integral plasma level of salicylic acid.