Studies on aztreonam in the perinatal period

Pharmacokinetic, bacteriological and clinical studies on aztreonam (AZT) in the perinatal period were carried out with the following summary of the results. Antibacterial effects of AZT on bacterial growth of Escherichia coli (MIC 12.5 micrograms/ml) and Pseudomonas aeruginosa (MIC 50 micrograms/ml) in amniotic fluid were determined and it was found that the activity of AZT is enhanced in amniotic fluid. AZT rapidly penetrated into tissues and sera of pregnant women upon intravenous (i.v.) injection and its maternal serum concentrations reached their peak levels shortly after the injection. Placental penetration of AZT to the fetus was good and, after single i.v. injection of 1 g, the concentrations of AZT in the umbilical cord serum and amniotic fluid exceeded MICs against major Gram-negative bacilli. These results indicate that single i.v. injection of AZT 1 g twice a day is effective for the treatment and prophylaxis of perinatal infections. Injection of AZT for the treatment of puerperal infections showed excellent clinical effectiveness with 100% eradication of aerobic Gram-negative rods. No side-effect was observed in any case. All of the results suggested clinical usefulness of AZT in the perinatal period.