Absence of a pharmacokinetic interaction between chloramphenicol and acetaminophen in children.

The pharmacokinetics of chloramphenicol (CAP; administered intravenously as chloramphenicol succinate, CAPS) was studied in 26 acutely ill febrile children 3 to 58 months of age who either did (n = 18) or did not (n = 8) receive acetaminophen (APAP) for antipyresis. CAP pharmacokinetics were evaluated after the first dose and at steady state. CAP serum levels were quantitated by high-performance liquid chromatography. There were no significant differences between groups (APAP vs non-APAP) or between first dose and steady-state evaluations for the elimination rate constant, serum half-life, apparent volume of distribution, and serum clearance of CAP. Likewise, there were no statistically significant differences when the APAP group was evaluated according to the presence or absence of APAP in serum before the first dose of CAP. Elimination of CAP in subjects with serum CAPS level less than 1 microgram/ml was similar in the first dose and steady-state evaluations and in the APAP and non-APAP groups. The presence or absence of CAPS or APAP did not affect the estimation of CAP elimination. Thus a pharmacokinetic interaction between CAP and APAP was not demonstrated in acutely ill febrile children during concomitant therapy.