Cefazolin pharmacokinetics in maternal plasma and amniotic fluid during pregnancy.
OBJECTIVE
To study cefazolin pharmacokinetics in maternal plasma and amniotic fluid during pregnancy.


METHODS
Newly collected time-concentrations profiles and reported studies investigating cefazolin disposition (plasma, amniotic fluid) were pooled. Nonlinear mixed effect modeling was applied. A 2-compartment linear disposition model was used to fit cefazolin plasma observations. A third compartment was used to model amniotic fluid concentration.


RESULTS
One hundred eighty-seven plasma and 96 amniotic fluid samples were collected in 82 pregnancies (17-40 weeks gestational age). Cefazolin clearance and distribution estimates were 7.44 L/h and 12.04 L without gestational age-dependent trends in maternal plasma. The equilibration half-life (T(eq)) between plasma and amniotic fluid at term gestational age was 4.4 hours, increased with decreasing gestational age, and was 9.09 times longer in patients with polyhydramnios.


CONCLUSIONS
Cefazolin clearance and distribution volume are increased during pregnancy. The cefazolin T(eq) depends on gestational age and polyhydramnios. On the basis of these observations, dosing regimes to attain higher amniotic fluid concentrations were formulated.
Allegaert
Karel
K
Division of Woman and Child, University Hospitals Leuven, Leuven, Belgium. karel.allegaert@uz.kuleuven.ac.be
van Mieghem
Tim
T
Verbesselt
Rene
R
de Hoon
Jan
J
Rayyan
Maissa
M
Devlieger
Roland
R
Deprest
Jan
J
Anderson
Brian J
BJ
D000653:Amniotic Fluid / Q000737:chemistry*; D000900:Anti-Bacterial Agents / Q000493:pharmacokinetics* / Q000627:therapeutic use; D002437:Cefazolin / Q000493:pharmacokinetics* / Q000627:therapeutic use; D005260:Female; D005315:Fetal Diseases / Q000601:surgery; D006801:Humans; D013513:Obstetric Surgical Procedures; D011247:Pregnancy / Q000097:blood*; D011251:Pregnancy Complications, Infectious / Q000517:prevention & control*
D000900:Anti-Bacterial Agents; D002437:Cefazolin