Therapeutic concentration of coumarin as antipyretic.

Using a model previously described the antipyretic effect of coumarin (C) was studied with administration by constant rate infusion. A parallel design was used in the present study with 6 rabbits each in the following groups: (1) control, (2) with C 0.06 mcg/ml as desired steady state concentration for I.V. infusion after a loading dose, (3) endotoxin 0.125 mg/kg I.V. push, and (4) C I.V. Infusion with 0.06 mcg/ml steady state concentration after a loading dose plus endotoxin 0.125 mg/kg I.V. push. C in presence of endotoxin challenge reduces the elevated temperature significantly throughout the entire time of the experiment. Whereas C alone does not cause lowering of normal body temperature, in febrile condition the elevated temperature is reduced to below baseline levels. Based on these and previous findings it is hypothesized that C exhibits an aspirin-like action.