Abstract: Aim Effect of different chronos on acetaminophen pharmacokinetics was studied. Methods After acetaminophen was given at 8:00 and 20: 00 by mouth, the drug concentrations in salivas were moni-tored and pharma kinetics parameters were calculated. Results Compared with at 20: 00, acetaminophen given at 8: 00 had more rapid absorption, shorter time of arriving at peak, but had worse absorption degree, greater clearance, and shorter mean residence time.

Key words: Acetaminophen, Chronos, Pharmacokinetics