The influence of fever on the pharmacokinetics of pranoprofen in elderly subjects.

Pranoprofen (75 mg) was given orally during febrile (mean body temperature 38.3 degrees C) and afebrile (mean body temperature 36.3 degrees C) periods in nine elderly subjects. Blood samples for plasma drug concentrations were taken for a 10 hour post-drug period. The mean elimination half-life (t1/2 beta) was significantly prolonged and the mean area under the time-concentration curve from 0 to 10 hrs (AUC0-10) was greater, although not significantly, during fever. No significant difference was observed in the time to maximum concentration (tmax), maximum plasma concentration (Cmax) or apparent volume of distribution (Vd/F) between the both dosages. There was a positive correlation (r = 0.448, 0.05 less than P less than 0.10) between the body temperature and t1/2 beta of pranoprofen. These data indicate that the clearance of pranoprofen is reduced during fever in elderly subjects.