Drug Exposure in Newborns: Effect of Selected Drugs Prescribed to Mothers During Pregnancy and Lactation

Maternal, fetal, neonatal and breastmilk flecainide concentration during maternal therapy and lactation: a case report

BACKGROUND

Mothers requiring the antiarrhythmic agent flecainide are often advised not to breastfeed, because of the lack of data concercing neonatal effects and flecainide plasma concentrations following maternal exposure as well as via lactation. This is the first report on combined maternal, fetal, neonatal and breastmilk flecainide concentrations in a breastfed infant of a mother requiring flecainide treatment.

CASE PRESENTATION

A 35-year old Gravida 2 Para 1, known with ventricular arrhythmia, was referred to our tertiary center at 35 + 4 weeks of gestation. Because of an increase of ventricular ectopy, oral metoprolol 11.9 milligrams once daily was switched to oral flecainide 87.3 milligrams twice daily. Weekly collected maternal flecainide plasma trough concentrations fell within the therapeutic range of 0.2 to 1.0 mg/L and no further clinically significant arrhythmias occurred during the study period. A healthy son was born at 39 weeks of gestation and had a normal electrocardiogram. The fetal to maternal flecainide ratio was 0.72 and at three different timepoints, the flecainide concentration was higher in breastmilk than in maternal plasma. The relative infant dose received via breastmilk compared to maternal dose was 5.6%. Neonatal plasma concentrations were not detectable, despite the flecainide passage into breastmilk. All electrocardiograms to assess the neonatal antiarrhytmic effect were normal.

CONCLUSIONS

Our results assume that flecainide can be prescribed safely to lactating mothers. Quantification of drug concentrations in neonatal blood in addition to measurements in maternal and fetal blood, and breastmilk, are helpful to evaluate the effects and safety of maternal medication use during pregnancy and lactation.

The Use of Antiepileptic Drugs During Pregnancy and Fetal Outcomes

Epilepsy affects approximately 1 percent of the population and roughly 1 million women of childbearing age. Estimates suggest that 0.3-0.7 percent of pregnancies occur in women with epilepsy. Epilepsy itself increases the risk of congenital malformation and medications add to this risk. Also, approximately one-half of the use of medications for epilepsy are used for other indications, possibly increasing exposure in some women. As controlled trials with these medications are not performed during pregnancy, data has been accumulated primarily through databases and case studies. This review is intended to update the practitioner about the use and concerns of antiepileptic medications in the presnant woman and the potential effects on the fetus and neonate.

Review of embryo-fetal developmental toxicity studies performed for pharmaceuticals approved by FDA in 2020 and 2021

103 novel drugs were approved by the FDA in 2020-2021. Embryofetal development (EFD) studies were conducted for 76% of these approvals. For the majority of drugs, EFD studies were conducted in rats and rabbits. Both species were equally sensitive to developmental toxicity, but the rabbit was slightly more sensitive to maternal toxicity at the same systemic exposure level. Nonetheless, 68% of drugs showed more than a 2-fold difference in the low adverse effect level for developmental toxicity between the rat and rabbit. Previous reviews in this series compiled information on EFD studies for all small molecule pharmaceuticals approved since 2014 and for all therapeutic monoclonal antibodies approved to date. The use of non-human primates for the developmental toxicity testing of biopharmaceuticals has fallen over recent years (22% of biologics license applications (BLAs) for 2020-2021, compared with 62% for 2002-2015), with more biopharmaceuticals now tested in rodents (37% of BLAs for 2020-2021). While the Pregnancy and Lactation Labeling Rule (PLLR), adopted in 2014, has brought consistency to the presentation of EFD data in drug labels, prescribers complain that the pregnancy section of current drug labels is neither concise nor clear. The FDA has pledged to address the concerns of clinicians in a future revision of the PLLR rule. The recommendations on risk assessment in the recently revised ICHS5(R3) guideline could be incorporated into the PLLR rule to remove extraneous nonclinical details from the label with the aim of facilitating rapid understanding by the practitioner.

Can Umbilical Cord and Meconium Results Be Directly Compared? Analytical Approach Matters

Maternal drug use during pregnancy is a significant concern. Drug-exposed newborns are often born premature and may suffer from birth defects, neonatal abstinence syndrome and cognitive and developmental delays. Because of this, testing of neonatal specimens is carried out to assess fetal drug exposure during pregnancy. Umbilical cord tissue (UC) and meconium are commonly used specimens for this purpose. However, comprehensive studies comparing drug positivity rates and concentration in the two specimen types are lacking. To this end, 4,036 paired UC and meconium specimens originating from 13 states within the USA were identified, and retrospective analysis of drug positivity rates and drug concentration was performed for 31 analytes in 5 drug classes. Testing for 11-Nor-9-carboxy-tetrahydrocannabinol (THC-COOH) is a separate orderable for UC specimen at our laboratory, so a second data set was created for evaluation of this drug analyte with 2,112 paired UC and meconium specimens originating from 11 states. Testing of UC was performed by semi-quantitative liquid chromatography-tandem mass spectrometry (LC-MS-MS) assays, whereas, for meconium, an immunoassay-based screening preceded LC-MS-MS confirmation tests. Results generated for UC and meconium specimens were therefore compared for a total of 32 drug analytes from 6 drug classes. Drug concentrations for analytes were higher in meconium compared to UC, with the exception of phencyclidine. Despite this, the positivity rates for individual analytes were higher in UC, with the exception of THC-COOH and cocaine. Furthermore, analysis for multidrug positivity revealed that THC-COOH and opioids were the most common multidrug combination detected in both matrices. In conclusion, this study suggests that for most drug compounds, UC was more analytically sensitive to assess neonatal drug exposure by current methodologies. Additionally, by demonstrating that meconium has higher drug concentrations for most compounds, this study sets the stage for developing more sensitive assays in meconium.

A phase 1, open-label study to evaluate the drug interaction between islatravir (MK-8591) and the oral contraceptive levonorgestrel/ethinyl estradiol in healthy adult females

Introduction

Hormonal contraceptives are among the most effective forms of reversible contraception, but many other compounds, including some antiretrovirals, have clinically meaningful drug–drug interactions (DDIs) with hormonal contraceptives. Islatravir is a novel human immunodeficiency virus nucleoside reverse transcriptase translocation inhibitor currently in clinical development for treatment and prevention of HIV infection. A phase 1 clinical trial was conducted to evaluate the DDI of islatravir and the combination of oral contraceptive levonorgestrel (LNG)/ethinyl estradiol (EE).

Methods

This was an open‐label, two‐period, fixed‐sequence, DDI clinical trial in healthy, postmenopausal or bilaterally oophorectomized females aged 18 through 65 years in the United States between October 2016 and January 2017. A single dose of LNG 0.15 mg/EE 0.03 mg was given followed by a 7‐day washout. Islatravir, 20 mg, was then dosed once weekly for 3 weeks; a single dose of LNG 0.15 mg/EE 0.03 mg was given concomitantly with the third dose of islatravir. Pharmacokinetic samples for plasma LNG and EE concentrations were collected pre‐dose and up to 120 hours post‐dose in each period. Safety and tolerability were assessed throughout the trial by clinical assessments, laboratory evaluations and examination of adverse events.

Results and Discussion

Fourteen participants were enrolled. The pharmacokinetics of LNG and EE were not meaningfully altered by co‐administration with islatravir. For the comparison of (islatravir + LNG/EE)/(LNG/EE alone), the geometric mean ratios (GMRs) (90% confidence intervals [CIs]) for LNG AUC_0–inf and C_max were 1.13 (1.06, 1.20) and 0.965 (0.881, 1.06), respectively. For EE, the GMRs (90% CI) for AUC_0–inf and C_max were 1.05 (0.981, 1.11) and 1.02 (0.971, 1.08), respectively. Co‐administration of all three drugs was generally well tolerated.

Conclusions

The results of this trial support the use of LNG/EE contraceptives in combination with islatravir without dose adjustment.

Successful pregnancy and follow-up after in vitro fertilization of a kidney transplant patient with systemic lupus erythematosus, primary biliary cholangitis, and hypothyroidism

This report describes the case of a female kidney transplant patient with systemic lupus erythematosus, primary biliary cholangitis, and postsurgical hypothyroidism due to Grave's disease who had a healthy newborn after in vitro fertilization (IVF). Cases of successful pregnancy involving women who underwent IVF after kidney transplantation have been reported. Normal and stable renal function, adequate immunosuppressant therapy, and well-managed blood pressure are requirements to be eligible for IVF and pregnancy. Primary biliary cholangitis without cirrhosis does not seem to worsen during pregnancy and IVF must be individualized in patients with systemic lupus erythematosus. There are no similar case reports involving kidney transplant patients or individuals with autoimmune disorders, so the decision to perform IVF had to be individualized in order to avoid complications for the mother and fetus.

Obstetrical, fetal, and lactation pharmacology-a crisis that can no longer be ignored

The data available to inform pregnant and lactating women about drug safety and efficacy are woefully inadequate. This lack of information encompasses every aspect of pharmaceutics, including limited human data about the embryonic risk, limited pharmacokinetic and pharmacodynamic information during and after pregnancy to ensure proper dosing, and a dearth of new medications to treat obstetrical and lactation disorders. This state of affairs has been longstanding and can be attributed to several realities, most of which have withstood any efforts to modify them. The first reality is the disinterest of the pharmaceutical industry to undertake pregnancy and lactation studies because of the considerable disincentives to undertake such studies. The medicolegal risks and the limited opportunity for financial gain are significant barriers to their participation. The US Food and Drug Administration has not mandated that new drugs or drugs "on patent" must include studies in pregnant women. Regulatory constrains that have defined pregnant women as a vulnerable class have greatly limited pharmacologic studies. Another contributing factor to this lack of information is the lack of researchers skilled in pharmacology with an interest in the pregnant woman. In addition, although difficult to measure, there is the hesitancy of pregnant and lactating women to participate in pharmacology research either for fear of fetal risk or an inability to commit the time required for such studies. Research in obstetrical and lactation pharmacology lags far behind that of pediatric pharmacology. Through the efforts of many, research in that field is highly funded and very productive in providing new information on medications used in children who, like pregnant women, have differing pharmacologic needs based on age (chronology for children and gestational age for pregnant women). Recently, the deficiencies and possible remedies for this embarrassing state of affairs in obstetrical and lactation pharmacology have been addressed by the federal government, which led to 15 recommendations from the Task Force on Research Specific to Pregnant Women and Lactating Women. In this article, we address the challenges in providing meaningful information about specific medications used by the mother and how these problems have evolved. We also suggest specific strategies to start the process of remediation.

Bipolar disorder: Treatment strategies for women of childbearing age

PURPOSE

Bipolar disorder is associated with increased rates of morbidity and mortality, magnified in women of childbearing age. The purpose of this paper is to provide an overview of the differential diagnosis and management of bipolar disorder in women of childbearing age.

CONCLUSIONS

Differential diagnoses for bipolar disorder include depressive disorders, anxiety disorders, trauma-related disorders, attention-deficit/hyperactivity disorder, and personality disorders. Pharmacotherapeutic options for the treatment of bipolar disorder include lithium, anti-epileptic medications, and atypical antipsychotics. In regard to women of childbearing age, consideration of risks, benefits, and alternative therapies is needed before initiating therapy.

PRACTICE IMPLICATIONS

Caring for patients with bipolar disorder, particularly women of childbearing age, requires careful differentiation of bipolar disorder from other mental health problems, and prudent consideration of pharmacotherapeutic options.

Low Content of Cyclosporine A and Its Metabolites in the Colostrum of Post-Transplant Mothers

The rate of post-transplant mothers who breastfeed while on immunosuppression is progressively increasing. Data on breastfeeding while on cyclosporine-based regimens are limited. Therefore, we assessed the amount of cyclosporine and its metabolites that might be ingested by a breastfed infant by measuring the concentration of cyclosporine and its metabolites in the colostrum of seven post-transplant mothers. The mean concentration of cyclosporine in the colostrum was 22.40 ± 9.43 mcg/L, and the estimated mean daily dose of the drug was 1049.22 ± 397.41 ng/kg/24 h. Only three metabolites (AM1, DHCsA, and THCsA) had mean colostrum amounts comparable to or higher than cyclosporine itself, with the daily doses being 468.51 ± 80.37, 2757.79 ± 1926.11, and 1044.76 ± 948.56 ng/kg/24 h, respectively. Our results indicate a low transfer of cyclosporine and its metabolites into the colostrum in the first two days postpartum and confirm the emerging change to the policy on breastfeeding among post-transplant mothers. A full assessment of the safety of immunosuppressant exposure via breastmilk will require further studies with long-term follow-ups of breastfed children.

Pharmacokinetics of HIV therapies in pregnant patients: an update

INTRODUCTION

Mother-to-child transmission (MTCT) of HIV is thought to account for over 90% of new pediatric infections, and is associated with poor maternal and fetal outcomes. As such ensuring further reduction in MTCT is a priority in HIV treatment and prevention programs.

AREAS COVERED

This review aims to provide a comprehensive update on the pharmacokinetics of recently approved antiretroviral drugs and novel drug formulations and delivery systems. Alongside recent recommendations for dose adjustments, and an overview of the implications of co-infections on the pharmacokinetics of antiretrovirals relevant to pregnant HIV positive patients. Additionally, potential opportunities to progress pharmacokinetic research of new treatments in this population are highlighted.

EXPERT OPINION

In order to improve our understanding of how to provide safe and effective treatment to HIV positive pregnant women, further work is required to enable their inclusion in early stages of clinical trials. Incentives must be created for this research, in the form of additional investment by key stakeholders and regulatory agencies. Furthermore, as the incidence of MTCT is reduced globally there is a need to conduct long-term pharmacovigilance studies in uninfected children exposed to HIV and antiretrovirals in utero, in order to determine the safest and most effective antiretroviral therapies.