Experience with cefotaxime in gynecology and obstetrics.

Minimal inhibitory concentrations of cefotaxime, determined against clinical isolates from gynecological and obstetrical infections, were less than or equal to 1.56 microgram/ml against about 65% of the aerobes tested. Against anaerobic organisms, the growth of about 65% of the strains was inhibited by less than or equal to 12.5 microgram/ml. The passage of cefotaxime into human uterine tissue was investigated after a single 1-gm intravenous (IV) injection. Peak concentration of 12.24 microgram/gm was attained after about 20 minutes. Passage to the pelvic cavity fluid was studied after a single 2-gm IV dose of cefotaxime. Peak concentration of 22.8 microgram/ml was obtained after about 80 minutes. The placental passage of cefotaxime after a single 1-gm IV injection also was investigated. Compared with the mother's serum concentration, cord serum concentration was about one fourth and amniotic fluid concentration about one tenth. A maximum concentration of 0.63 microgram/ml was seen in the neonate. Clinical response rates were extremely favorable: 98% against uterine infections, 94% against adnexitis, 91% against pelvic infections, and 93% against external genital infections. Bacteriological effectiveness by pathogen was likewise high, showing eradication rates of 95% against gram-positive aerobes, 88% against gram-negative aerobes, and 96% against gram-negative anaerobes.