Pharmacokinetics and Target Attainment of Antimicrobial Drugs Throughout Pregnancy. Part II: Cephalosporins

Understanding the pharmacokinetics (PK) of antibiotics in pregnant women is essential for safe and effective treatment. This review is part of a series that evaluates the PK, exposure, and target attainment of antibiotics during pregnancy. Part II focuses on cephalosporins and investigates if evidence-based dosing regimens are developed.

A systematic literature search was conducted using PubMed on 24 July 2025. Articles containing PK data on pregnant women treated with any of the 35 selected cephalosporins were classified as relevant. Extracted PK and target attainment parameters included volume of distribution (Vd), clearance (CL), drug concentrations, area under the curve, elimination half-life (t_1/2), probability of target attainment, and proposed dosing regimens.

Of 219 articles identified, 44 met the inclusion criteria, covering 14 out of 35 cephalosporins. During second (T2) and third (T3) trimesters of pregnancy, Vd (9.2-18.4%) and CL (30.8-100%) were higher compared with nonpregnant, first trimester, or postpartum women. Consequently, reduced target attainment was reported in T2 and T3 pregnant women. Evidence-based dosing regimens were proposed for pregnant women receiving cefazolin, cefuroxime, cefoxitin, ceftazidime, cephradine, cefatrizine, and ceftizoxime.

During pregnancy, an increase in Vd and CL was observed, indicating a potential need for higher or additional dosages, or shorter dosing intervals to achieve target attainment. However, evidence-based dosing adjustments were identified for only seven cephalosporins. These findings highlight significant gaps in knowledge and underscore the need for further research to characterize PK profiles and establish dosing recommendations for the remaining cephalosporins in pregnant women.