Antipyresis: Its effect on mortality rate of bacterially infected rabbits

Abstract

The effect of an antipyretic drug administered directly into the preoptic-anterior hypothalamus was measured in order to investigate the role of fever on mortality of bacterially infected mammals. New Zealand white rabbits ( Oryctolagus cuniculus) were injected intravenously with Pasteurella multocida and either sodium salicylate or a control solution was infused directly into the preoptic-anterior hypothalamus. Both groups developed fevers, but the fever of the rabbits infused with the antipyretic was reduced by 50% during the initial stage of infection. Hypothalamic sodium salicylate infusions produced a lower average fever than control infusions over an initial 5 hour period of infection, reducing average 5 hour fevers from 1.56° to 0.72°C. All of the infected rabbits infused with sodium salicylate died whereas only 29% of the infected control rabbits died. Rabbits receiving sodium salicylate alone did not die. The increased mortality could possibly be the result of a fulminating infection caused by rapidly multiplying bacteria during the initial, attenuated phase of the febrile course in the salicylate-treated rabbits.