Single-dose pharmacokinetics of piperacillin and tazobactam in infants and children.
The pharmacokinetics of piperacillin and tazobactam were assessed after single-dose administration to 47 infants and children. Study subjects ranging in age from 2 months to 12 years were randomized to receive one of two different doses of a piperacillin-tazobactam combination (8:1): a low dose (n = 23) of 50 and 6.25 mg of piperacillin and tazobactam per kg of body weight, respectively, or a high dose (n = 24) of 100 and 12.5 mg, respectively. The pharmacokinetic behavior of tazobactam was very similar to that observed for piperacillin, supporting the use of these two agents in a fixed-dose combination. No differences in the pharmacokinetics of piperacillin or tazobactam were observed between the two doses administered. The elimination parameters half-life and total body clearance decreased and increased, respectively, with increasing age, whereas volume parameters (volume of distribution and steady-state volume of distribution) remained relatively constant for both compounds. The primary metabolite of tazobactam, metabolite M1, was measurable in the plasma of 18 of the 47 study subjects; 17 of these 18 subjects received the high doses. More than 70% of the administered piperacillin and tazobactam doses were excreted unchanged in the urine over a 6-h collection period. These data combined with the known in vitro susceptibilities of a broad range of pediatric bacterial pathogens indicate that a dose of 100 mg of piperacillin and 12.5 of mg tazobactam per kg of body weight administered as a fixed-dose combination every 6 to 8 h would be appropriate to initiate clinical efficacy studies in infants and children for the treatment of systemic infections arising outside of the central nervous system.
Reed
M D
MD
Division of Pediatric Pharmacology, Rainbow Babies and Childrens Hospital, Cleveland, OH 44106-6010, USA.
Goldfarb
J
J
Yamashita
T S
TS
Lemon
E
E
Blumer
J L
JL
D002648:Child; D002675:Child, Preschool; D006801:Humans; D007223:Infant; D008657:Metabolic Clearance Rate; D008826:Microbial Sensitivity Tests; D010397:Penicillanic Acid / Q000031:analogs & derivatives* / Q000493:pharmacokinetics; D010878:Piperacillin / Q000493:pharmacokinetics* / Q000494:pharmacology; D000078142:Tazobactam; D065093:beta-Lactamase Inhibitors
D065093:beta-Lactamase Inhibitors; D010397:Penicillanic Acid; D000078142:Tazobactam; D010878:Piperacillin