EFFECTS OF DIFLUNISAL ON FEVER IN THE RABBIT AND THE RAT

The antipyretic efficacy of diflunisal was assessed in rats made febrile by yeast and in rabbits made febrile by bacterial [Shigella dysenteriae] endotoxin. Diflunisal was a more potent antipyretic than aspirin in rats, reducing a maximum fever in doses not producing overt toxic effects. Submaximal fever in rabbits was not reduced by diflunisal. Fatal hyperthermia of rapid onset was observed in rats and rabbits receiving high doses of diflunisal after administration of microbial pyrogen but not in control animals. The toxicity of diflunisal may be potentiated by the presence of pyrogens. The apparent antipyretic efficacy of a drug can evidently depend on the species-pyrogen combination used to screen for antipyresis.