Comparative pharmacokinetics of cefoxitin in postpartum normotensive and pregnancy-induced hypertensive patients.

Limited pharmacokinetic data exist on cefoxitin, a semisynthetic cephamycin antibiotic, in the obstetric patient. Thirteen normotensive and five subjects with severe pregnancy-induced hypertension were identified within the first two postpartum days after cesarean section. After a 2 gm intravenous infusion, serial samples of blood were obtained and analyzed for cefoxitin by high-pressure liquid chromatography. Peak cefoxitin concentrations after infusion were 53.3 +/- 18.6 and 50.8 +/- 25.2 micrograms/ml for the normotensive and pregnancy-induced hypertensive groups, respectively. The only significant difference in pharmacokinetic parameters between these groups was a higher serum trough concentration of cefoxitin in the patients with pregnancy-induced hypertension as compared to the normotensive group. Because of diminished trough levels in our study patients, attention may need to be given to the adjustment of dosages in postpartum women with serious infections.