Pharmacokinetic and clinical studies on aztreonam in the perinatal period in obstetrics and gynecology

Pharmacokinetic and clinical studies on aztreonam (AZT) in the perinatal period in obstetrics and gynecology were performed with the following results. 1. Concentrations of AZT in maternal serum, umbilical cord serum, amniotic fluid and neonatal serum were determined after 1 hour intravenous drip infusion of 1 g. The maternal serum concentration was 32.2 micrograms/ml at 26 minutes after administration, gradually decreasing thereafter to 13.2 micrograms/ml at 2 hours 33 minutes, 4.9 micrograms/ml at 3 hours 21 minutes and 2.9 micrograms/ml at 5 hours 3 minutes. Umbilical cord serum concentration was 17.0 micrograms/ml at 36 minutes after drip infusion and still remained at 4.0-16.1 micrograms/ml at 5 hours after administration. Amniotic fluid concentration was 9.9 micrograms/ml at 3 hours 21 minutes after drip infusion and showed 3.3 micrograms/ml at 16 hours 26 minutes after administration. Most of the maximum serum concentrations of newborns between 3 to 24 hours after delivery were not detectable, with only one case with 2.2 micrograms/ml at 9 hours after delivery. 2. AZT 1 or 2 g x 2/day was given by intravenous drip infusion to 12 cases of perinatal infections in obstetrics and gynecology for 5 to 8 days. Clinical efficacies were evaluated as excellent in 8 cases, effective in 2 and not effective in 2 with 83.3% efficacy rate. With respect to side effects, minor degree of urticaria was observed in 1 case. Another case showed a transient elevations of GOT, GPT and Al-P in laboratory tests.