Transfer of cefotaxime in human milk and from mother to foetus

The transfer of cefotaxime into human milk was studied in 12 healthy breast-feeding mothers. Following intravenous administration of 1.0 g of cefotaxime peak milk concentrations were measured at 2 or 3 h. Peaks ranged from 0.25 to 0.52 mg/l (mean 0.35 ± 0.09). The maternal-foetal transfer of cefotaxime was investigated in 14 healthy gravid as at 15 to 24 weeks' gestation. Cefotaxime was administered as a single 1.0 g intravenous dose in 10 and as multiple doses of 1–0 g every 6 h in 4 cases. Antibiotic concentrations were higher after multiple doses in maternal serum and foetal tissues. Foetal antibiotic levels were less than 6.7 mg/l in serum, less than 6.3 μg/g in kidney, less than 2.4 μg/g in lung and less than 2.1 mg/l in CSF, being lower in other tissues. Amniotic fluid levels were less than 3.3 mg/l and placental levels were less than 2.45 μg/g. Half-life in foetal serum was calculated as 2.3 h and in amniotic fluid 2.8 h. Cefotaxime concentrations in breast milk could affect the oropharyngeal flora of the suckling infant, and they are bactericidal in foetal tissues.