Vol. 38, No. 5, 1995 Printed ill U.S.A.ml.zh), CAZ clearance per kg (40.9 ± 6.1 mLih/kg versus 60.8 ± 8.3 mLih/kg), and the GFR expressed in mLimin (3.14 ± 0.43 versus 4.73 ± 0.89) were significantly (p < 0.001) decreased in the asphyxiated newborn. We conclud e that twice daily administration of 50 rug/kg of body weight CAZ given to asphyxiated term newborns in the first days of life results in significantly higher serum trough levels in comparison with control infants. The impaired CAZ clea rance is a result of a significantly decreased GFR. Perinat al asphyxia is a result of complicated or traumatic deliveries and may exert profound effects on renal and liver function. McCance and Widd owson (1) reported as early as 1954 a reducti on in the GFR, a poor urea clearance , and a low urine output in full-term and postmature infants after prolonged and difficult labor. A redistribution of the fetal circulation leading to an increas ed blood flow to the brain, heart, and adrenals and a concomitantly decrea sed blood flow to the lungs, intestines, and kidneys is responsi ble for this asphyxiainduced renal impairment (2). Several drugs such as the f3-l actam antibiotic CAZ are primar ily excrete d by the kidneys. CAZ, a broad spectrum cephalosporin, is an antibiotic frequentl y used for the treatment of infectious diseases in newborn infants. The currently recommended dosage for CAZ in term infants is 50-150 mglkg of body weight per day in two or