Pharmacokinetic and clinical evaluation of serious infections in prematureand newborn infants under therapy with imipenem/cilastatin

Efficacy and pharmacokinetic parameters of imipenem/cilastatin (I/C) were i nvestigated in a retrospective evaluation in 104 premature and newborn infa nts. Patients enrolled in this investigation constituted a particularly hig h risk group with extreme prematurity, perinatal asphyxia and amnion infect ion as well as various malformations. In 15 of the 104 infants serum concen trations were measured far drug monitoring and determination of optimal tot al daily dosage. A total daily dose of 50 mg/kg birth weight for premature and newborn infants divided into two doses led to imipenem peak concentrati ons of 17.7 mg/l +/- 9.2 mg/l (range: 1.95-38.05) and trough levels were 2. 35 mg/l +/- 1.02 (range 2.34-10.88) in premature infants. Imipenem peak con centrations of 20.6 +/- 10.8 (range 3.94-32.3) and trough levels of 0.43 +/ - 0.17 (range 0.16-0.94) were measured in newborns. The half-life of elimin ation was 3.3 h and 1.86 h, respectively. Six of the 104 treated patients d ied, five of them of ca uses un related to infection. Seizures occurred in 8.9% of patients during therapy with I/C com pared with 5.8% of a large sur vey of premature and newborn infants in our intensive ca re unit (ICU). How ever, the severity of illness of these two groups cannot be compared. I/C c an be expected to constitute effective therapy in premature and newborn inf ants with serious nosocomial infections even after failure of other broad s pectrum antibiotics.