FUNDAMENTAL AND CLINICAL STUDIES OF CEFSULODIN IN THE NEONATES AND PREMATURE INFANTS

Fourteen neonates and premature infants with ages ranging 1 to 28 days were intravenously given one shot injection of 20mg/kg of cefsulodin (CFS). Plasma and urine levels and recovery rates of CFS were determined in the first 6 hours after administration. For prophylaxis of infection, a daily average dose of 52.8mg/kg of CFS was injected intravenously to 3 neonates with ages ranging 2 to 16 days in 2 to 3 divided doses during an average period of 7 days. Along with observations of prophylactic effects on infection, side effects and abnormalities in laboratory test values were examined. The results obtained are summarized below: 1. Of the 9 patients with birth weight of 2,500g or above, the plasma levels peaked in 6 patients at 5 minutes, in 2 patients at 15 minutes and in the other at 1 hour after administration, with peak levels ranging between 35.8 and 60.6μg/ml. Subsequently, gradual decreases or bimodal tapering changes were noted in the plasma levels. The cause of the delay in the occurrence of maximum peak observed in the 3 patients at 15 minutes or 1 hour after administration and the cause of the appearance of bimodal tapering changes in 3 subjects are not known. A tendency was observed that the younger the age of subject was, the larger the AUC and the longer the half-life became. Half-lives in all 9 neonates were longer than those in average infants who were given intravenous injection at the same dose. 2. Of 5 patients with birth weight of less than 2,500g, the determination of peak plasma levels was not performed in those within 7 days after birth. Plasma levels, however, were observed to reach their peaks in 4 patients at 5 minutes and in another at 15 minutes after administration, the levels ranging between 41.5 and 56.0μg/ml. Subsequently to this, gradual decreases and bimodal tapering changes of plasma levels were noted. The cause of the delay in plasma levels to reach their maximum peaks values in the 1 patient to 15 minutes after administration and the cause of occurrence of bimodal tapering changes in the 2 partients are not known. A tendency was observed that the younger the age of subjects was, the larger the AUC and the longer the half-life became. This tendency was similar to that observed in the group with birth weight of 2,500g or above. Half-lives in all 5 neonates were longer than those in average infants who were given intravenous injection at the same dose. 3. Urine levels of the drug were measurable in 9 patients with birth wei