Influence of pregnancy on ceftriaxone, cefazolin and gentamicin pharmacokinetics in caesarean vs. non-pregnant sectioned women

Maternal-Fetal Exposure to Antibiotics: Levels, Mother-to-Child Transmission, and Potential Health Risks

Due to its widespread applications in various fields, antibiotics are continuously released into the environment and ultimately enter the human body through diverse routes. Meanwhile, the unreasonable use of antibiotics can also lead to a series of adverse outcomes. Pregnant women and developing fetuses are more susceptible to the influence of external chemicals than adults. The evaluation of antibiotic exposure levels through questionnaire surveys or prescriptions in medical records and biomonitoring-based data shows that antibiotics are frequently prescribed and used by pregnant women around the world. Antibiotics may be transmitted from mothers to their offspring through different pathways, which then adversely affect the health of offspring. However, there has been no comprehensive review on antibiotic exposure and mother-to-child transmission in pregnant women so far. Herein, we summarized the exposure levels of antibiotics in pregnant women and fetuses, the exposure routes of antibiotics to pregnant women, and related influencing factors. In addition, we scrutinized the potential mechanisms and factors influencing the transfer of antibiotics from mother to fetus through placental transmission, and explored the adverse effects of maternal antibiotic exposure on fetal growth and development, neonatal gut microbiota, and subsequent childhood health. Given the widespread use of antibiotics and the health threats posed by their exposure, it is necessary to comprehensively track antibiotics in pregnant women and fetuses in the future, and more in-depth biological studies are needed to reveal and verify the mechanisms of mother-to-child transmission, which is crucial for accurately quantifying and evaluating fetal health status.

Physiologic Changes During Pregnancy and Impact on Small-Molecule Drugs, Biologic (Monoclonal Antibody) Disposition, and Response

Pregnancy is a unique physiological state that results in many changes in bodily function, including cellular, metabolic, and hormonal changes. These changes can have a significant impact on the way small-molecule drugs and monoclonal antibodies (biologics) function and are metabolized, including efficacy, safety, potency, and adverse effects. In this article, we review the various physiologic changes that occur during pregnancy and their effects on drug and biologic metabolism, including changes in the coagulation, gastrointestinal, renal, endocrine, hepatic, respiratory, and cardiovascular systems. Additionally, we discuss how these changes can affect the processes of drug and biologic absorption, distribution, metabolism, and elimination (pharmacokinetics), and how drugs and biologics interact with biological systems, including mechanisms of drug action and effect (pharmacodynamics) during pregnancy, as well as the potential for drug-induced toxicity and adverse effects in the mother and developing fetus. The article also examines the implications of these changes for the use of drugs and biologics during pregnancy, including consequences of suboptimal plasma drug concentrations, effect of pregnancy on the pharmacokinetics and pharmacodynamics of biologics, and the need for careful monitoring and individualized drug dosing. Overall, this article aims to provide a comprehensive understanding of the physiologic changes during pregnancy and their effects on drug and biologic metabolism to improve the safe and effective use of drugs.

Optimizing Therapeutic Drug Monitoring in Pregnant Women: A Critical Literature Review

BACKGROUND

More than 90% of pregnant women take at least one drug during pregnancy. Drug dose adjustments during pregnancy are sometimes necessary due to various pregnancy-induced physiological alterations frequently associated with lower plasma concentrations. However, the clinical relevance or benefits of therapeutic drug monitoring (TDM) in pregnant women have not been specifically studied. Clinical pharmacokinetic studies in pregnant women are incredibly challenging for many reasons. Despite this, regulatory agencies have made efforts to encourage the inclusion of this population in clinical trials to achieve more information on the pharmacotherapy of pregnant women. This review aims to provide support for TDM recommendations and dose adjustments in pregnant women.

METHODS

The search was conducted after a predetermined strategy on PubMed and Scopus databases using the MeSH term "pregnancy" alongside other terms such as "Pregnancy and dose adjustment," "Pregnancy and therapeutic drug monitoring," "Pregnancy and PBPK," "Pregnancy and pharmacokinetics," and "Pregnancy and physiological changes."

RESULTS

The main information on TDM in pregnant women is available for antiepileptics, antipsychotics, antidepressants, antibiotics, antimalarials, and oncologic and immunosuppressive drugs.

CONCLUSIONS

More data are needed to support informed benefit-risk decision making for the administration of drugs to pregnant women. TDM and/or pharmacokinetic studies could ensure that pregnant women receive an adequate dosage of an active drug. Mechanistic modeling approaches potentially could increase our knowledge about the pharmacotherapy of this special population, and they could be used to better design dosage regimens.

Group B streptococcus in obstetrics: unsolved problems

For several decades, among all possible pathogens of neonatal infections, group B streptococcus has been one of the leading positions. Sepsis, meningitis, and pneumonia are among the most common clinical manifestations of neonatal infection associated with group B streptococcus. In this review, our goal was to analyze the literature demonstrating a worldwide approach to the prevention of vertical transmission of group B streptococcus from mother to child. When writing the review, scientific publications of foreign and domestic authors from the PubMed database were studied. The review considers the drugs of choice for intranatal antibiotic prophylaxis, and their pharmacodynamic, and pharmacokinetic features. The analysis details the problem of the growth of resistance of group B streptococcus to antibacterial drugs. The antimicrobial activity of lactoferrin was noted at a minimum inhibitory concentration of 500 μg/ml. The presented review also reflects the protective and therapeutic effects of oral intake of probiotics containing Lactobacillus acidophilus, Lactobacillus salivarius, Lactobacillus rhamnosus GR-1, and Lactobacillus reuteri RC-14 . Based on the analysis, it can be concluded that penicillin G and ampicillin have the most pronounced bactericidal effect against group B streptococcus. At the same time, the most common side effects of β-lactam penicillins include an allergic reaction with the possible development of anaphylactic shock. Given this, the antibiotics of the first-line reserve group include cefazolin, clindamycin, and vancomycin. At the same time, it is important to take into account the decrease in the therapeutic concentration of clindamycin with a change in the alpha-1-acid glycoprotein in the blood of the mother and fetus, the nephrotoxic effect of vancomycin and the cross-a llergic reaction of cefazolin with antibiotics of the penicillin group. A promising direction in solving the problem of group B streptococcus is the development of new strategies for the prevention of perinatal infection of the fetus and newborn based on a more detailed study of the effects of lactoferrin and probiotics.

The Pharmacokinetics and Target Attainment of Antimicrobial Drugs Throughout Pregnancy: Part III Non-penicillin and Non-cephalosporin Drugs

INTRODUCTION

Understanding the pharmacokinetics (PK) of antimicrobial drugs in pregnant women is crucial to provide effective and safe treatment. This study is part of a series that systematically reviews literature on the PK and analyzes if, based on the changed PK, evidence-based dosing regimens have been developed for adequate target attainment in pregnant women. This part focusses on antimicrobials other than penicillins and cephalosporins.

METHODS

A literature search was conducted in PubMed according to the PRISMA guidelines. Search strategy, study selection, and data extraction were independently performed by two investigators. Studies were labeled as relevant when information on the PK of antimicrobial drugs in pregnant women was available. Extracted parameters included bioavailability for oral drugs, volume of distribution (Vd) and clearance (CL), trough and peak drug concentrations, time of maximum concentration, area under the curve and half-life, probability of target attainment, and minimal inhibitory concentration (MIC). In addition, if developed, evidence-based dosing regimens were also extracted.

RESULTS

Of the 62 antimicrobials included in the search strategy, concentrations or PK data during pregnancy of 18 drugs were reported. Twenty-nine studies were included, of which three discussed aminoglycosides, one carbapenem, six quinolones, four glycopeptides, two rifamycines, one sulfonamide, five tuberculostatic drugs, and six others. Eleven out of 29 studies included information on both Vd and CL. For linezolid, gentamicin, tobramycin, and moxifloxacin, altered PK throughout pregnancy, especially in second and third trimester, has been reported. However, no target attainment was studied and no evidence-based dosing developed. On the other hand, the ability to reach adequate targets was assessed for vancomycin, clindamycin, rifampicin, rifapentine, ethambutol, pyrazinamide, and isoniazid. For the first six mentioned drugs, no dosage adaptations during pregnancy seem to be needed. Studies on isoniazid provide contradictory results.

CONCLUSION

This systematic literature review shows that a very limited number of studies have been performed on the PK of antimicrobials drugs-other than cephalosporins and penicillins-in pregnant women.

Understanding the pharmacokinetics of antibiotics in pregnancy: Is there a role for therapeutic drug monitoring? A narrative review

PURPOSE

Antibiotics are commonly used during pregnancy. However, physiological changes during pregnancy can affect the pharmacokinetics of drugs, including antibiotics, used during this period. Pharmacokinetic evaluations have shed light on how antibiotics are affected during pregnancy and have influenced dosing recommendations in this context. Methods: A narrative review was conducted and included reports providing data reflecting drug distribution and exposure in the context of pregnancy. Results: Pharmacokinetic parameters of antibiotics in pregnancy and transplacental passage of antibiotics are comprehensively presented. Conclusion: Knowledge about the impact on pharmacokinetics and fetal exposure is especially helpful for complicated or severe infections, including intra-amniotic infection and sepsis in pregnancy, where both mother and fetus are at risk. Further studies are warranted to consolidate the role of therapeutic drug monitoring in complicated or severe infections in pregnant patients.

Anti-Infective Dosing in Special Populations: Pregnancy

Substantial anatomical and physiological changes occur during pregnancy and labor, which impact on drug absorption, distribution, metabolism, and elimination. Reduced maternal concentrations may have a clinically important impact on the efficacy of anti-infectives for mother, fetus, and neonate, with potential dosing implications. However, there is a paucity of pregnancy-specific data examining this. Existing data on the pharmacokinetics of anti-infectives in pregnancy are summarized and evaluated, with emphasis on agents that are used in treatment of HIV, tuberculosis, malaria, and common bacterial infections. Limitations and challenges in achieving ideal study designs in pregnant populations are highlighted, and key quality considerations for the generation of the highest quality evidence are outlined. PubMed was searched for each chosen anti-infective. Pharmacokinetic studies which either compared pharmacokinetics from pregnant women against nonpregnant controls, or which assessed concentrations against a known minimum inhibitory concentration were included. Two independent reviewers extracted data from each study and appraised them using the 24-point ClinPK Checklist. The main finding was that there is a lack of published data for anti-infectives in pregnancy, despite their clinical importance. Of the studies identified, only those investigating cobicistat-boosted antiretroviral regimens firmly concluded that these should not be used in pregnancy. Most studies concluded either that further research was needed, or that there were significant pharmacokinetic differences between pregnant and nonpregnant participants which had uncertain clinical significance. Challenges in applying existing quality grading systems to these studies were noted, suggesting a development of a refined system for appraisal of pharmacokinetic studies in "special populations" may be warranted.

Calculating the appropriate prophylactic dose of cefazolin in women undergoing cesarean delivery

BACKGROUND AND OBJECTIVES

Surgical site infection and other postoperative complications are relatively common in obstetrical procedures, and they are associated with morbidity, prolonged hospital stay, and readmissions. Appropriate levels of antimicrobial agents given directly before skin incision can prevent the establishment of surgical-related infection caused by endogenous microorganisms present on the woman's skin. We aimed to determine serum concentrations of cefazolin given to pregnant women prior to scheduled cesarean delivery and to compare their drug concentrations and pharmacokinetics in 2 weight groups.

STUDY DESIGN

We conducted a prospective cohort analysis of the pharmacokinetics of cefazolin in women undergoing cesarean delivery (August 2017 to September 2018). One or two grams of intravenous cefazolin was administered within 30 min prior to skin incision to women weighing <80 kg and ≥80 kg, respectively. Maternal serum samples were obtained at skin incision and 30 min later. The serum concentration of cefazolin was measured by high-pressure liquid chromatography. Antimicrobial coverage was defined as being appropriate when the cefazolin levels were above the minimal inhibitory concentration. Pharmacokinetic parameters were estimated using a one-compartment model.

RESULTS

A total of 61 women were enrolled, of whom 47 underwent cesarean delivery (study group). The mean time that had elapsed between drug administration to incision was 13 ± 6.9 min (95% confidence interval 10.6-16.2 min). The drug levels after 30 min in women who weighed >80 kg and in women who received 2 g cefazolin, after 30 min from incision differed significantly (87.0 ± 26.0 vs 55.4 ± 16.6 μg/ml, p = .0001).

CONCLUSION

A single 1- or 2-g dose of cefazolin provides serum concentrations above minimal inhibitory concentrations for susceptible pathogens in most women undergoing scheduled cesarean delivery.

Preliminary physiologically based pharmacokinetic modeling of renally cleared drugs in Chinese pregnant women

AIM

The aim of this study was to build and verify a preliminary physiologically based pharmacokinetic (PBPK) model of Chinese pregnant women. The model was used to predict maternal pharmacokinetics (PK) of 6 predominantly renally cleared drugs.

METHOD

Based on SimCYP Caucasian pregnancy population dataset, the preliminary Chinese pregnant population was built by updating several key parameters and equations according to physiological parameters of Chinese (or Japanese) pregnant women. Drug-specific parameters of 6 renally cleared drugs were validated through PBPK modeling of Caucasian non-pregnant, Caucasian pregnant and Chinese non-pregnant population. The preliminary PBPK model of Chinese pregnant population was then developed by integrating the preliminary Chinese pregnant population and the drug-specific parameters. This model was verified by comparing the predicted maternal PK of these 6 drugs with the observed in vivo data from the literature.

RESULTS

The preliminary Chinese pregnant population PBPK model successfully predicted the PK of 6 target drugs for different pregnancy stages. The predicted plasma concentrations time profiles fitted the observed data well, and most predicted PK parameters were within 2-fold of observed data.

CONCLUSIONS

The preliminary Chinese pregnant population PBPK model provided a useful tool to predict the maternal PK of 6 predominantly renally cleared drugs in Chinese pregnant women.

Pregnancy-related pharmacokinetics and antimicrobial prophylaxis during fetal surgery, cefazolin and clindamycin as examples

Antimicrobial prophylaxis during surgery aims to prevent post-operative site infections. For fetal surgery, this includes the fetal and amniotic compartments. Both are deep compartments as drug equilibrium with maternal blood is achieved relatively late. Despite prophylaxis, chorio-amnionitis or endometritis following ex utero intrapartum treatment or fetoscopy occur in 4.13% and 1.45% respectively of the interventions. This review summarizes the observations on two commonly administered antimicrobials (cefazolin, clindamycin) for surgical prophylaxis during pregnancy, with emphasis on the deep compartments. For both compounds, antimicrobial exposure is on target when we consider the maternal and fetal plasma compartment. In contrast, amniotic fluid concentrations-time profiles display a delayed and much more blunted pattern, behaving as deep compartment. For cefazolin, there are data that document further dilution in the setting of polyhydramnios. Along this deep compartment concept, there is some accumulation during repeated administration, modeled for cefazolin and observed for clindamycin. The relative underexposure to antimicrobials in amniotic fluid may be reflected in the pattern of maternal-fetal complications after fetal surgery, and suggest that antimicrobial prophylaxis practices for fetal surgery should be reconsidered. Further studies should be designed by a multidisciplinary team (fetal surgeons, clinical pharmacologists and microbiologists) to facilitate efficient evaluation of antimicrobial prophylaxis.

The transplacental passage of commonly used intrapartum antibiotics and its impact on the newborn management: A narrative review

Neonates exposed to intra-amniotic infection are at increased risk of early-onset sepsis. Administration of antibiotics to the mother may offer some protection, however a comprehensive description of the determinants influencing their transplacental passage and delivery to the fetus has not been performed. While penicillin G, ampicillin, cefazolin and gentamicin reach therapeutic levels in the fetal serum rapidly following maternal administration, the transfer of second-line intrapartum antimicrobials, such as vancomycin and clindamycin, is slower and less predictable. Erythromycin, used in the context of preterm premature rupture of the membranes, has suboptimal influx into the fetal compartment. This evidence is predominantly drawn from term pregnancies and situations of low infectious risk; however, prematurity may negatively influence fetal exposure to intrapartum antibiotics. Optimal fetal antimicrobial concentrations to target are poorly defined and the extent to which our review findings apply to preterm early-onset neonatal sepsis prevention is unclear. Interpretation of blood cultures drawn in neonates with expected circulating levels of maternal antimicrobials above the minimal inhibitory concentration for Group B Streptococcus is challenging despite the use of contemporary optimized blood culture media.

Prevention of Group B Streptococcal Early-Onset Disease in Newborns: ACOG Committee Opinion, Number 782

Group B streptococcus (GBS) is the leading cause of newborn infection. The primary risk factor for neonatal GBS early-onset disease (EOD) is maternal colonization of the genitourinary and gastrointestinal tracts. Approximately 50% of women who are colonized with GBS will transmit the bacteria to their newborns. Vertical transmission usually occurs during labor or after rupture of membranes. In the absence of intrapartum antibiotic prophylaxis, 1-2% of those newborns will develop GBS EOD. Other risk factors include gestational age of less than 37 weeks, very low birth weight, prolonged rupture of membranes, intraamniotic infection, young maternal age, and maternal black race. The key obstetric measures necessary for effective prevention of GBS EOD continue to include universal prenatal screening by vaginal-rectal culture, correct specimen collection and processing, appropriate implementation of intrapartum antibiotic prophylaxis, and coordination with pediatric care providers. The American College of Obstetricians and Gynecologists now recommends performing universal GBS screening between 36 0/7 and 37 6/7 weeks of gestation. All women whose vaginal-rectal cultures at 36 0/7-37 6/7 weeks of gestation are positive for GBS should receive appropriate intrapartum antibiotic prophylaxis unless a prelabor cesarean birth is performed in the setting of intact membranes. Although a shorter duration of recommended intrapartum antibiotics is less effective than 4 or more hours of prophylaxis, 2 hours of antibiotic exposure has been shown to reduce GBS vaginal colony counts and decrease the frequency of a clinical neonatal sepsis diagnosis. Obstetric interventions, when necessary, should not be delayed solely to provide 4 hours of antibiotic administration before birth. This Committee Opinion, including , , and , updates and replaces the obstetric components of the CDC 2010 guidelines, "Prevention of Perinatal Group B Streptococcal Disease: Revised Guidelines From CDC, 2010."

Antibiotic therapy as personalized medicine - general considerations and complicating factors

The discovery of antibiotic drugs is considered one of the previous century's most important medical discoveries (Medicine's 10 greatest discoveries. New Haven, CT: Yale University Press, 1998: 263). Appropriate use of antibiotics saves millions of lives each year and prevents infectious complications for numerous people. Still, infections kill unacceptable many people around the world, even in developed countries with easy access to most antibiotic drugs. Optimal use of antibiotics is dependent on the identification of primary and secondary focus, and knowledge on which pathogens to expect in a specific infectious syndrome and information on general patterns of regional antibiotic resistance. Furthermore, sampling for microbiological analysis, knowledge of patient immune status and organ functions, travel history, pharmacokinetics and -dynamics of the different antibiotics and possible biofilm formation are among several factors involved in antibiotic therapy of infectious diseases. The present review aims at describing important considerations when using antibacterial antibiotics and to describe how this is becoming substantially more personalized. The parameters relevant in considering the optimal use of antibiotics to treat infections are shown in Fig. 1 - leading to the most relevant antibiotic therapy for that specific patient. To illustrate this subject, the present review's focus will be on challenges with optimal dosing of antibiotics and risks of underdosing. Especially, in cases highly challenging for achieving the aimed antibiotic effect against bacterial infections - this includes augmented renal clearance (ARC) in sepsis, dosing challenges of antibiotics in pregnancy and against biofilm infections.

Effect of Maternal Obesity on Maternal-Fetal Transfer of Preoperative Cefazolin at Cesarean Section

OBJECTIVES

American Congress of Obstetricians and Gynecologists recommends a single dose of antibiotic prophylaxis before all cesarean sections (C/S). This recommendation is based on pharmacokinetic studies that include only non-obese patients. We sought to evaluate 1) cefazolin plasma concentrations among obese and non-obese patients after administration of a 2-g cefazolin dose for prevention of surgical wound infections, and 2) whether cefazolin concentration in fetal circulation may be protective against pathogens that cause early onset neonatal sepsis.

METHODS

Maternal and fetal cefazolin plasma concentrations were compared between obese (body mass index [BMI] ≥ 30 kg/m²) and non-obese (BMI < 25 kg/m²) healthy, term pregnant women undergoing scheduled C/S. Liquid chromatographic-tandem mass spectrometric (LC-MS/MS) methods were used for quantification of total and free cefazolin concentrations in maternal blood (MB) and umbilical cord blood (UCB).

RESULTS

Eight women were screened and consented. There was no difference between groups in MB total and free cefazolin concentrations. All MB samples had total and free cefazolin concentrations greater than the minimum inhibitory concentration 90 (MIC90) for Group B Streptococcus (GBS), Staphylococcus aureus, and Escherichia coli. All UCB samples had total and free cefazolin concentrations greater than MIC90 for GBS and S aureus, even when administered as briefly as 18 minutes before delivery. A lower concentration of total cefazolin was detected in UCB of neonates of obese women compared to non-obese women (p > 0.05).

CONCLUSIONS

Administration of 2 g of cefazolin to women undergoing scheduled C/S might be an adequate prophylactic dose for surgical wound infection in both non-obese and obese patients; and cefazolin concentration in fetal circulation may be protective against GBS and S aureus.

Pregnancy-Associated Changes in Pharmacokinetics: A Systematic Review

BACKGROUND

Women are commonly prescribed a variety of medications during pregnancy. As most organ systems are affected by the substantial anatomical and physiological changes that occur during pregnancy, it is expected that pharmacokinetics (PK) (absorption, distribution, metabolism, and excretion of drugs) would also be affected in ways that may necessitate changes in dosing schedules. The objective of this study was to systematically identify existing clinically relevant evidence on PK changes during pregnancy.

METHODS AND FINDINGS

Systematic searches were conducted in MEDLINE (Ovid), Embase (Ovid), Cochrane Central Register of Controlled Trials (Ovid), and Web of Science (Thomson Reuters), from database inception to August 31, 2015. An update of the search from September 1, 2015, to May 20, 2016, was performed, and relevant data were added to the present review. No language or date restrictions were applied. All publications of clinical PK studies involving a group of pregnant women with a comparison to nonpregnant participants or nonpregnant population data were eligible to be included in this review. A total of 198 studies involving 121 different medications fulfilled the inclusion criteria. In these studies, commonly investigated drug classes included antiretrovirals (54 studies), antiepileptic drugs (27 studies), antibiotics (23 studies), antimalarial drugs (22 studies), and cardiovascular drugs (17 studies). Overall, pregnancy-associated changes in PK parameters were often observed as consistent findings among many studies, particularly enhanced drug elimination and decreased exposure to total drugs (bound and unbound to plasma proteins) at a given dose. However, associated alterations in clinical responses and outcomes, or lack thereof, remain largely unknown.

CONCLUSION

This systematic review of pregnancy-associated PK changes identifies a significant gap between the accumulating knowledge of PK changes in pregnant women and our understanding of their clinical impact for both mother and fetus. It is essential for clinicians to be aware of these unique pregnancy-related changes in PK, and to critically examine their clinical implications.

Quantification of cefazolin in serum and adipose tissue by ultra high performance liquid chromatography-Tandem mass spectrometry (UHPLC-MS/MS): application to a pilot study of obese women undergoing cesarean delivery

Higher doses of cefazolin are required in obese patients for preoperative antibiotic prophylaxis, owing to its low lipophilicity. An ultra high performance liquid chromatography-tandem mass spectrometry method was developed to quantify cefazolin in serum and adipose tissue from 6 obese patients undergoing cesarean delivery, and using stable-isotope labeled cefazolin as an internal standard. The method has a 2μg/g lower limit of quantitation. The concentration in adipose tissue was 3.4±1.6μg/mL, which is less than half of the reported minimum inhibitory concentration of 8μg/mL for cefazolin. Serum cefazolin concentrations were more than 30-fold higher than in adipose tissue.

Bioanalytical development and validation of liquid chromatographic-tandem mass spectrometric methods for the quantification of total and free cefazolin in human plasma and cord blood

OBJECTIVES

Cefazolin is a commonly prescribed β-lactam antibiotic for prophylaxis against skin infections following surgery, including caesarean sections. Assessment of maternal and neonatal exposure is important for correlating drug concentrations to clinical outcomes. Thus, bioanalytical methods for the quantification of both total and free cefazolin in maternal plasma and cord blood can assist in the comprehensive evaluation of cefazolin exposure.

DESIGN AND METHODS

Specimen preparation for the measurement of total cefazolin was performed via protein precipitation with acetonitrile containing the internal standard cloxacillin. Ultrafiltration was used to isolate free cefazolin. Processed samples were analyzed on a Prelude SPLC system coupled to a TSQ triple quadrupole Vantage mass spectrometer. Methods were validated following FDA bioanalytical guidelines.

RESULTS

The analytical measuring ranges of these methods were 0.48-480 µg/mL and 0.048-48 µg/mL for total and free drug, respectively. Calibration curves were generated using 1/x² weighted linear regression analysis. Total cefazolin demonstrated inter- and intra-assay precision of ≤20% at the LLOQ and ≤11.2% at other levels. Free cefazolin demonstrated inter- and intra-assay precision of ≤18.5% at the LLOQ and ≤12.6% at other levels, respectively. Accuracy (%DEV), carryover, matrix effects, recovery and stability studies were also acceptable based on FDA recommendations. Furthermore, it was demonstrated that samples prepared in cord blood can be accurately quantified from an adult plasma calibration curve, with recoveries ≤9.1% DIF and ≤11.9% DIF for total and free cefazolin, respectively.

CONCLUSIONS

The described LC-MS/MS methods allow for the measurement of total and free cefazolin in both plasma and cord blood.

Intrapartum GBS screening and antibiotic prophylaxis: a European consensus conference

Group B streptococcus (GBS) remains worldwide a leading cause of severe neonatal disease. Since the end of the 1990s, various strategies for prevention of the early onset neonatal disease have been implemented and have evolved. When a universal antenatal GBS screening-based strategy is used to identify women who are given an intrapartum antimicrobial prophylaxis, a substantial reduction of incidence up to 80% has been reported in the USA as in other countries including European countries. However recommendations are still a matter of debate due to challenges and controversies on how best to identify candidates for prophylaxis and to drawbacks of intrapartum administration of antibiotics. In Europe, some countries recommend either antenatal GBS screening or risk-based strategies, or any combination, and others do not have national or any other kind of guidelines for prevention of GBS perinatal disease. Furthermore, accurate population-based data of incidence of GBS neonatal disease are not available in some countries and hamper good effectiveness evaluation of prevention strategies. To facilitate a consensus towards European guidelines for the management of pregnant women in labor and during pregnancy for the prevention of GBS perinatal disease, a conference was organized in 2013 with a group of experts in neonatology, gynecology-obstetrics and clinical microbiology coming from European representative countries. The group reviewed available data, identified areas where results were suboptimal, where revised procedures and new technologies could improve current practices for prevention of perinatal GBS disease. The key decision issued after the conference is to recommend intrapartum antimicrobial prophylaxis based on a universal intrapartum GBS screening strategy using a rapid real time testing.

Pharmacokinetics of prophylactic cefazolin in parturients undergoing cesarean delivery

The objectives of this work were (i) to characterize the pharmacokinetics of cefazolin in pregnant women undergoing elective cesarean delivery and in their neonates; (ii) to assess cefazolin transplacental transmission; (iii) to evaluate the dosing and timing of preoperative, prophylactic administration of cefazolin to pregnant women; and (iv) to investigate the impact of maternal dosing on therapeutic duration and exposure in newborns. Twenty women received 1 g of cefazolin preoperatively. Plasma concentrations of total cefazolin were analyzed from maternal blood samples taken before, during, and after delivery; umbilical cord blood samples obtained at delivery; and neonatal blood samples collected 24 h after birth. The distribution volume of cefazolin was 9.44 liters. [corrected] The values for pre- and postdelivery clearance were 7.18 and 4.12 liters/h, respectively. Computer simulations revealed that the probability of maintaining free cefazolin concentrations in plasma above 8 mg/liter during scheduled caesarean surgery was <50% in the cord blood when cefazolin was administered in doses of <2 g or when it was administered <1 h before delivery. Therapeutic concentrations of cefazolin persisted in neonates >5 h after birth. Cefazolin clearance increases during pregnancy, and larger doses are recommended for surgical prophylaxis in pregnant women to obtain the same antibacterial effect as in nonpregnant patients. Cefazolin has a longer half-life in neonates than in adults. Maternal administration of up to 2 g of cefazolin is effective and produces exposure within clinically approved limits in neonates.

The EPIIC hypothesis: intrapartum effects on the neonatal epigenome and consequent health outcomes

There are many published studies about the epigenetic effects of the prenatal and infant periods on health outcomes. However, there is very little knowledge regarding the effects of the intrapartum period (labor and birth) on health and epigenetic remodeling. Although the intrapartum period is relatively short compared to the complete perinatal period, there is emerging evidence that this time frame may be a critical formative phase for the human genome. Given the debates from the National Institutes of Health and World Health Organization regarding routine childbirth procedures, it is essential to establish the state of the science concerning normal intrapartum epigenetic physiology. EPIIC (Epigenetic Impact of Childbirth) is an international, interdisciplinary research collaboration with expertise in the fields of genetics, physiology, developmental biology, epidemiology, medicine, midwifery, and nursing. We hypothesize that events during the intrapartum period - specifically the use of synthetic oxytocin, antibiotics, and cesarean section - affect the epigenetic remodeling processes and subsequent health of the mother and offspring. The rationale for this hypothesis is based on recent evidence and current best practice.

Policy statement—Recommendations for the prevention of perinatal group B streptococcal (GBS) disease

The Centers for Disease Control and Prevention (CDC) guidelines for the prevention of perinatal group B streptococcal (GBS) disease were initially published in 1996. The American Academy of Pediatrics (AAP) also published a policy statement on this topic in 1997. In 2002, the CDC published revised guidelines that recommended universal antenatal GBS screening; the AAP endorsed these guidelines and published recommendations based on them in the 2003 Red Book. Since then, the incidence of early-onset GBS disease in neonates has decreased by an estimated 80%. However, in 2010, GBS disease remained the leading cause of early-onset neonatal sepsis. The CDC issued revised guidelines in 2010 based on evaluation of data generated after 2002. These revised and comprehensive guidelines, which have been endorsed by the AAP, reaffirm the major prevention strategy--universal antenatal GBS screening and intrapartum antibiotic prophylaxis for culture-positive and high-risk women--and include new recommendations for laboratory methods for identification of GBS colonization during pregnancy, algorithms for screening and intrapartum prophylaxis for women with preterm labor and premature rupture of membranes, updated prophylaxis recommendations for women with a penicillin allergy, and a revised algorithm for the care of newborn infants. The purpose of this policy statement is to review and discuss the differences between the 2002 and 2010 CDC guidelines that are most relevant for the practice of pediatrics.

Preoperative administration of cephalosporins for elective caesarean delivery

INTRODUCTION

Antibiotic prophylaxis means administration of antibiotics in prevention of infections.

OBJECTIVE

To investigate the efficacy of a single dose preoperative administration of ceftriaxone and cefazolin in the prevention of intra- and postoperative infections in the parturients without high risk of inflammation.

METHODS

The first group of 45 pregnant and 4 non-pregnant women were preoperatively administered ceftriaxone in a dose of 2 g, i.v., 10 minutes before the planned surgery. The second group of 45 pregnant and 4 non-pregnant women were preoperatively administered cefazolin in a dose of 2 g i.v., 10 minutes before the planned surgery. The concentrations of antibiotics were estimated immediately and 6 hours following the operation, as well as in the amniotic fluid and umbilical cord in the group of pregnant women. The estimation of antibiotic concentration was done by the method of liquid chromatography.

RESULTS

The mean concentrations of antibiotics in the patients following the elective caesarean section were as follows: ceftriaxone--22.7 microg/I. vs cefazolin--44.8 microg/l. Six hours later, the concentration of antibiotic decreased, but the concentration of cefazolin was still over the MIC for sensitive bacteria. The mean concentrations of antibiotics following gynaecological surgery in the non-pregnant patients were as follows: ceftriaxone--12.0 microg/I vs cefazolin--30.1 microg/l. Six hours later, the concentration of antibiotic decreased.

CONCLUSION

It is most optimal to administer a single-dose of the first generation cephalosporins -cefazolin- immediately following the clamping of the umbilical cord as well as in preoperative prophylaxis in gynaecological operations.

Arthropod borne disease: the leading cause of fever in pregnancy on the Thai-Burmese border

Background

Fever in pregnancy is dangerous for both mother and foetus. In the 1980's malaria was the leading cause of death in pregnant women in refugee camps on the Thai-Burmese border. Artemisinin combination therapy has significantly reduced the incidence of malaria in the population. The remaining causes of fever in pregnancy are not well documented.

Methodology

Pregnant women attending antenatal care, where weekly screening for malaria is routine, were invited to have a comprehensive clinical and laboratory screen if they had fever. Women were admitted to hospital, treated and followed up weekly until delivery. A convalescent serum was collected on day 21. Delivery outcomes were recorded.

Principal Findings

Febrile episodes (n = 438) occurred in 5.0% (409/8,117) of pregnant women attending antenatal clinics from 7-Jan-2004 to 17-May-2006. The main cause was malaria in 55.5% (227/409). A cohort of 203 (49.6% of 409) women had detailed fever investigations and follow up. Arthropod-borne (malaria, rickettsial infections, and dengue) and zoonotic disease (leptospirosis) accounted for nearly half of all febrile illnesses, 47.3% (96/203). Coinfection was observed in 3.9% (8/203) of women, mostly malaria and rickettsia. Pyelonephritis, 19.7% (40/203), was also a common cause of fever. Once malaria, pyelonephritis and acute respiratory illness are excluded by microscopy and/or clinical findings, one-third of the remaining febrile infections will be caused by rickettsia or leptospirosis. Scrub and murine typhus were associated with poor pregnancy outcomes including stillbirth and low birth weight. One woman died (no positive laboratory tests).

Conclusion/Significance

Malaria remains the leading cause of fever in pregnancy on the Thai-Burmese border. Scrub and murine typhus were also important causes of fever associated with poor pregnancy outcomes. Febrile pregnant women on the Thai-Burmese border who do not have malaria, pyelonephritis or respiratory tract infection should be treated with azithromycin, effective for typhus and leptospirosis.

Fever during pregnancy can be harmful for the mother and the infant. In resource poor settings health workers have very few field-based tests that help them identify the cause of infection. This study examined the causes of fever in pregnant women using laboratory support that is typically unavailable to most women living in the tropics. On the Thai-Burmese border there has been a great reduction in malaria in the last 20 years. However malaria remained the leading cause of fever in pregnancy in this study conducted between 2004 and 2006. Urinary tract infection was also a common cause of fever as it is in resource rich countries. Other diseases transmitted by mosquitoes (dengue), ticks (scrub and murine typhus), or rodents (leptospirosis) were common. Scrub and murine typhus were associated with stillbirth and low birth weight. Microscopy remains the most useful tool in the field for the diagnosis of fever in pregnant women. Leptospirosis, dengue and rickettsial infections require improved field-based diagnostic tools to ensure that women receive appropriate antibiotic therapy.

In vitro and in vivo methods to measure the ceftriaxone distribution into the rat tail intervertebral disc

To characterize the pathway of ceftriaxone penetration into intervertebral discs, rat-tail discs were collected and immersed in a ceftriaxone solution for an in vitro study. For this in vivo experiment, plasma and tail discs were collected 30 min after ceftriaxone administration (463.2 mg/kg, equal to 500 mg/kg disodium salt, iv). The ceftriaxone levels in the plasma and discs were determined with HPLC by a reversed-phase C18 column and a mobile phase of methanol and a 10 mM K(2)HPO(4) solution (pH 6.7) (21:79, v/v). The results indicate that ceftriaxone was undetectable by the in vitro model. The concentrations of ceftriaxone in plasma and in intervertebral discs were 147.4 ± 21.2 and 4.0 ± 1.7 µg/mL (as disodium salt), respectively. Our results suggest that a sufficient blood supply is required for the passive diffusion of ceftriaxone into intervertebral discs. The concentration ratio of ceftriaxone in intervertebral disc-to-plasma was about 2.7% at 30 min after ceftriaxone disodium administration (500 mg/kg, iv).

Infections in Pregnancy

Despite advances in peripartum care, maternal morbidity and mortality associated with infections in pregnancy are increasing even in developed countries. Recently published data from the Center for Disease Control's Pregnancy Mortality Surveillance System indicates that although maternal mortality from hemorrhage, embolism, and anesthesia has declined in the United States, the proportion of maternal deaths due to infections has increased. During 1991–7 infection accounted for 13.2% of pregnancy-related deaths overall and 36.3% of abortion-related deaths. The greatest infection risk is found in blacks, older women, women without prenatal care, and women with multiple pregnancy. In the United States pregnancy rates are stable or increasing in these groups. Infection is also a major cause of morbidity and mortality for the fetus and newborn. Many perinatal infections are associated with intra-uterine growth retardation and low birthweight, or cause fetal and neonatal brain injury. Infections, particularly bacterial vaginosis and chorioamnionitis, can result in preterm delivery of live-born infants (delivery before 37 weeks gestation), or stillbirth. A multitude of immunologic, endocrinologic, metabolic, physiologic, and anatomic changes influence the likelihood and course of many infections during pregnancy. Some of these changes are intrinsic, and occur in all normal pregnancies, while others occur to varying degrees in normal and abnormal pregnancies.

Cefazolin pharmacokinetics in maternal plasma and amniotic fluid during pregnancy

OBJECTIVE

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

STUDY DESIGN

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.

CONCLUSION

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.