Pharmacokinetics of cefotaxime, moxalactam, and cefoperazone in the early puerperium.

Twelve parturient women volunteered to receive 1 g of cefotaxime on the second or third day postpartum by intravenous infusion over 3 min. Blood was taken from the antecubital vein of the contralateral arm at 0.25, 0.5, 0.75, 1, 2, 4, and 6 h. The concentration of cefotaxime in serum was assayed by agar diffusion, with Sarcina lutea ATCC 9341 as the indicator strain. The same 12 women received an identical dose of antibiotic 4 months after the first dose, and blood was taken at the same time intervals as in the first study to measure antibiotic levels. An additional 24 women participated in identical studies with either moxalactam or cefoperazone. Cefoperazone afforded the highest concentration in serum of the three drugs, followed by moxalactam. These differences in the concentration in serum were seen both early postpartum and 4 months later. However, the concentration in serum of all three drugs was diminished 2 and 3 days postpartum compared with 4 months postpartum. Most pharmacokinetic parameters were also significantly altered early in the puerperium relative to those obtained 4 months later. The altered pharmacokinetic behavior of antibiotics associated with pregnancy appears to persist into the early puerperium.