THE EFFECT OF CAFFEINE ON THE PHARMACOKINETICS OF ACETAMINOPHEN IN MAN

The influence of caffeine (60 mg) was studied on the pharmacokinetic c haracteristics of acetaminophen (500 mg single dose) in ten healthy ma le human volunteers in a complete cross-over design. A high-performanc e liquid chromatography (HPLC) method was used to analyse serum drug c oncentrations. Caffeine caused a highly significant (p < 0.01) increas e in AUC and AUMC, a significant (p < 0.05) increase in C-max, and a s ignificant (p < 0.05) decrease in clearance (C1/F) of acetaminophen. W e conclude that caffeine taken in doses commonly available commerciall y or in a cup of coffee can significantly potentiate the therapeutic p otential of acetaminophen in man.