Maternal and fetal pharmacokinetics of moxalactam given intrapartum

Antibiotic use in pregnancy

With a few notable exceptions, most antibiotics can be used with relative safety during pregnancy. Moreover, none of the antibiotics to date has been shown to be teratogenic, although tetracycline may cause yellow-brown discoloration of the deciduous teeth (a fetal effect). Thus, antibiotics should not be withheld from the pregnant woman, especially when indicated for serious, life-threatening infections.

Diastereomeric beta-lactam antibiotics. Analytical methods, isomerization and stereoselective pharmacokinetics

Stereospecific HPLC methods for the determination of various diastereomeric beta-lactam antibiotics are reviewed. Stereoselectivity in the absorption, distribution and excretion of several diastereomeric beta-lactams is summarized. The isomerization of beta-lactam isomers and its influence on the pharmacokinetics and pharmacodynamics are discussed.

Steady-state cord and amniotic fluid ceftizoxime levels continuously surpass maternal levels

As part of our management protocol for preterm premature rupture of membranes, ceftizoxime and tocolysis were used to prolong the latent period and prevent or treat concomitant infection. Ceftizoxime was selected for this protocol based on its physiochemical properties, which favor placental transfer of the drug. Patients achieving steady-state pharmacodynamics (more than three doses of the drug) were considered eligible for study. Ceftizoxime levels were determined by reverse-phase high-pressure liquid chromatography. All levels measured after the first hour of treatment were indicative of the relative concentration of ceftizoxime in the fetal and amniotic fluid compartments when compared with the maternal compartment. Mean (+/- SEM) ceftizoxime levels were 11.96 + 2.35 micrograms/ml in maternal serum, 24.54 +/- 4.78 micrograms/ml in cord serum, and 43.45 +/- 4.97 micrograms/ml in amniotic fluid. Based on its broad antibacterial activity and its high concentration in fetal blood and amniotic fluid, ceftizoxime appears to be an ideal agent for treatment of the intrauterine environment.

Pharmacokinetics of cefoxitin in patients at term gestation: lavage versus intravenous administration

Despite the increasing popularity of antibiotic prophylaxis to reduce febrile morbidity in patients who undergo cesarean delivery, little is known of the pharmacokinetics of antibiotics in the patient at term gestation. This study was designed to elucidate the pharmacokinetics of cefoxitin when administered intravenously or by uterine and peritoneal lavage at cesarean section. Significant differences were found in the values for total body clearance area under the serum concentration-time curve (AUC), and K21 of cefoxitin administered intravenously to pregnant patients at term gestation compared to values for these parameters observed in nonpregnant patients. The concentration of cefoxitin in decidual tissue after uterine and peritoneal lavage with the antibiotic was 92.5 +/- 10.1 micrograms/gm (mean +/- SEM), whereas the concentration of cefoxitin in decidual tissue after intravenous administration of the antibiotic was 36.9 +/- 10.5 micrograms/gm (mean +/- SEM). This difference is statistically significant (p less than 0.05). We conclude that the pharmacokinetics of cefoxitin are altered in the pregnant patient as evidenced by the increased rapidity of clearance of the antibiotic (total body clearance for cefoxitin in pregnant patients, 20.41 L/hr). Moreover, uterine and peritoneal lavage results in significant tissue concentrations of antibiotic, which is of potential importance since the decidua is a presumed site of initiation of bacterial infection after cesarean section.

Comparison of cefoperazone and cefoxitin concentrations in serum and pelvic tissue of abdominal hysterectomy patients

Cefoperazone and cefoxitin concentrations were determined in serum and pelvic tissue samples obtained at various intervals after a 2-g intramuscular dose. These levels were determined in 59 women scheduled for elective abdominal hysterectomy. Concentrations were measured by a new high-pressure liquid chromatography method which correlated with the microbiological assay. The mean times (+/- standard deviation) of specimen collection were 188.5 +/- 61 and 185.5 +/- 55 min for cefoperazone and cefoxitin, respectively. The mean serum levels (+/- standard deviation) were 60.8 +/- 18.0 and 14.6 +/- 8.6 micrograms/ml, respectively. For cefoperazone, the mean pelvic tissue concentration was 19.8 micrograms/g. The mean pelvic tissue concentration for cefoxitin was 7.8 micrograms/g. The ratio of tissue concentration to serum concentration varied from 0.220 to 0.469 for cefoperazone and from 0.176 to 1.031 for cefoxitin. Although the serum and tissue concentrations of cefoperazone were much higher than those of cefoxitin, a greater portion of cefoxitin remained in the tissue. The tissue levels of both cefoperazone and cefoxitin were above the minimum inhibitory concentration of most sensitive pathogens several hours after a single prophylactic dose of either antibiotic.