Pharmacokinetic and clinical evaluations of ceftriaxone in perinatal infections in obstetrics and gynecology

Ceftriaxone (CTRX), an injectable cephem antibiotic agent, was studied for its pharmacokinetic properties and clinical usefulness in perinatal infections in obstetrics and gynecology on a multicenter basis. The study results are summarized below. 1. Following the one-shot intravenous injection of CTRX 1 g to pregnant women before labor, the maternal serum level of CTRX reached a peak at 131.8 micrograms/ml soon after the injection then it began to decrease gradually. T 1/2 was 6.7 hours. The umbilical serum level reached a peak at 16.0 micrograms/ml at 4.9 hours post-dose and decreased gradually with a half-life of 8.1 hours. The umbilical serum level was higher than the maternal serum level at about 12 hours post-dose. The amniotic fluid level reached a peak of 9.6 micrograms/ml at 12.8 hours post-dose. T 1/2 was 15.2 hours. The amniotic fluid level at about 15 hours post-dose or later exceeded the maternal serum level and was almost equal to the umbilical serum level at 24 hours post-dose. 2. Clinical usefulness was evaluated in 79 evaluable cases out of 89 treated for various infections at puerperium or for prophylaxis of infections at cesarean section or premature rupture of membranes (PROM). The efficacy rate was 100% in 7 cases of prenatal infections such as urinary tract infection and 30 cases of postnatal infections such as puerperal intrauterine infections. In 42 cases treated for prophylaxis in cases of cesarean section or PROM, the efficacy rate was 92.9%. Bacteriologically, 29 strains of pathogens were isolated from 26 cases. The disappearance rate of the pathogens was 96.0% as 23 strains were eradicated, 1 strain was substituted and no change was observed in 1 strain with unknown results in 4 strain. Skin rash and itching appeared in 1 patient as an adverse effect (1.1%). There were 10 cases of abnormal clinical laboratory test results such as elevated transaminase level were observed in 7 patients (7.9%). From the results, CTRX was considered to be a useful drug for the perinatal infection in the obstetrics and gynecology fields.