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Updated: Jun 24, 2026

Comprehensive Evaluation of the Effectiveness and Safety of Placenta-Targeted Drug Delivery Using Three Complementary Methods
Published on: September 10, 2018
Cefazolin plasma protein binding saturability during pregnancy.
Karel Allegaert1, Tim Van Mieghem, Rene Verbesselt
1Neonatal Intensive Care Unit, Division of Woman and Child, University Hospitals Leuven, Leuven, Belgium. karel.allegaert@uz.kuleuven.ac.be
This study found that pregnant individuals have a higher unbound fraction of cefazolin (CFZ) in their plasma compared to nonpregnant adults. Lower albumin levels during pregnancy likely explain this increased free cefazolin concentration.
Area of Science:
- Pharmacokinetics
- Maternal-fetal medicine
Background:
- Plasma protein binding influences drug efficacy and safety.
- Understanding cefazolin (CFZ) binding during pregnancy is crucial for optimizing maternal and fetal health.
Purpose of the Study:
- To quantify cefazolin (CFZ) plasma protein binding in pregnant individuals.
- To identify factors affecting CFZ binding during pregnancy.
- To compare CFZ binding in pregnancy with nonpregnant adults.
Main Methods:
- Analysis of 130 maternal plasma samples collected during in utero surgery.
- Correlation and multiple regression analyses to identify covariates of unbound CFZ fraction.
- Comparison of pregnancy data with historical data from nonpregnant adults.
Main Results:
- The median unbound CFZ fraction was 0.25 during pregnancy, higher than in nonpregnant adults (0.19).
- Significant correlations were found between unbound CFZ fraction and total CFZ concentration, time after administration, albuminemia, and gestational age.
- Lower albumin levels during pregnancy were identified as a key factor for increased unbound CFZ.
Conclusions:
- Cefazolin (CFZ) plasma protein binding is saturable during pregnancy.
- The unbound fraction of cefazolin is significantly higher in pregnant individuals, primarily due to decreased albumin levels.
- These findings have implications for cefazolin dosing and therapeutic drug monitoring in pregnant patients.
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