SEQUENTIAL, SINGLE-DOSE PHARMACOKINETIC EVALUATION OF MEROPENEM IN HOSPITALIZED INFANTS AND CHILDREN

Meropenem is a new carbapenem antibiotic which possesses a broad spect rum of antibacterial activity against many of the pathogens responsibl e for pediatric bacterial infections, In order to define meropenem dos ing guidelines for children, an escalating, single-dose, pharmacokinet ic study at 10, 20, and 40 mg/kg of body weight was performed. A total of 73 infants and children in four age groups were enrolled in the st udy: 2 to 5 months, 6 to 23 months, 2 to 5 years, and 6 to 12 years, T he first patients enrolled were those in the oldest age group, who rec eived the lowest dose, Subsequent enrollment was determined by decreas ing age and increasing dose, Complete studies were performed on 63 pat ients, No age- or dose-dependent effects on pharmacokinetic parameter estimates were noted, Mean pharmacokinetic parameter estimates were as follows: half-life, 1.13 +/- 0.15 h; volume of distribution at steady state, 0.43 +/- 0.06 liters/kg; mean residence time, 1.57 +/- 0.11 h; clearance, 5.63 +/- 0.75 ml/min/kg; and renal clearance, 2.53 +/- 0.5 0 ml/min/liters kg, Approximately 55% of the administered dose was rec overed as unchanged drug in the urine during the 12 h after dosing, No significant side effects were reported in any patients, By using the derived pharmacokinetic parameter estimates, a dose of 20 mg/kg given every 8 h will maintain plasma meropenem concentrations above the MIC that inhibits 90% of strains tested for virtually all potentially susc eptible bacterial pathogens.