Challenges of studying drugs in pregnancy for off-label indications: pravastatin for preeclampsia prevention

Microfluidic technology and simulation models in studying pharmacokinetics during pregnancy

Introduction: Preterm birth rates and maternal and neonatal mortality remain concerning global health issues, necessitating improved strategies for testing therapeutic compounds during pregnancy. Current 2D or 3D cell models and animal models often fail to provide data that can effectively translate into clinical trials, leading to pregnant women being excluded from drug development considerations and clinical studies. To address this limitation, we explored the utility of in silico simulation modeling and microfluidic-based organ-on-a-chip platforms to assess potential interventional agents. Methods: We developed a multi-organ feto-maternal interface on-chip (FMi-PLA-OOC) utilizing microfluidic channels to maintain intercellular interactions among seven different cell types (fetal membrane-decidua-placenta). This platform enabled the investigation of drug pharmacokinetics in vitro. Pravastatin, a model drug known for its efficacy in reducing oxidative stress and inflammation during pregnancy and currently in clinical trials, was used to test its transfer rate across both feto-maternal interfaces. The data obtained from FMi-PLA-OOC were compared with existing data from in vivo animal models and ex vivo placenta perfusion models. Additionally, we employed mechanistically based simulation software (Gastroplus®) to predict pravastatin pharmacokinetics in pregnant subjects based on validated nonpregnant drug data. Results: Pravastatin transfer across the FMi-PLA-OOC and predicted pharmacokinetics in the in silico models were found to be similar, approximately 18%. In contrast, animal models showed supraphysiologic drug accumulation in the amniotic fluid, reaching approximately 33%. Discussion: The results from this study suggest that the FMi-PLA-OOC and in silico models can serve as alternative methods for studying drug pharmacokinetics during pregnancy, providing valuable insights into drug transport and metabolism across the placenta and fetal membranes. These advanced platforms offer promising opportunities for safe, reliable, and faster testing of therapeutic compounds, potentially reducing the number of pregnant women referred to as "therapeutic orphans" due to the lack of consideration in drug development and clinical trials. By bridging the gap between preclinical studies and clinical trials, these approaches hold great promise in improving maternal and neonatal health outcomes.

Patterns of Medication Use and Their Determinants in Pregnancy among Women Admitted to the Obstetrics Wards of a Tertiary Care Hospital: A Cross-Sectional Study: Patterns of Medication Use and Their Determinants in Pregnancy

Background

To assess the patterns and factors affecting medication use during antenatal and perinatal periods and to examine maternal and fetal outcomes among pregnant women admitted to a tertiary care hospital in a developing country.

Methods

A cross-sectional study was conducted in the obstetrics wards from 2017 to 2019. Data on patient demographics, co-existent medical conditions, medications, and patient outcomes were collected. Descriptive statistics were used to analyze baseline data, chi-square test was used for categorical variables, and multivariate logistic regression was used for factors influencing drug prescription.

Results

Out of 442 pregnant women, 56% were primigravida with a mean age of 24.7 ± 3.9 years. Approximately 32% experienced at least one disease condition during pregnancy; hypothyroidism (9.7%) was the commonest. The mean number of medications was 2.7 and 38.9% received drugs for a disease condition. Antimicrobials (24.5%) were the commonest drug class. Maternal age of over 25 [(OR (CI): 1.508 (1.191–2.716) ( p = .005)] and maternal illness [OR (CI) 2.934 (1.8–4.7) ( p = .00)] were identified as factors affecting drug prescription. Approximately 39.8% of deliveries were cesarean. Of the newborns, 12.6% had low birth weight, 9.2% were admitted to the newborn intensive care unit, and 14.9% were premature.

Conclusions

Most patients were primigravida and under 25 years. Antimicrobials were the most prescribed drug class. Maternal age over 25 years and maternal illness were identified as the factors affecting medication use. The prevalence of cesareans and prematurity was similar to previous studies.

Statins in Pregnancy: Can We Justify Early Treatment of Reproductive Aged Women?

PURPOSE OF REVIEW

Statins are the pillar of secondary prevention in reducing cardiovascular disease in high-risk adults. However, statin discontinuation is the standard recommendation in pregnant and lactating patients. This review evaluates whether we can justify the early treatment of reproductive aged women with statin therapy.

RECENT FINDINGS

Statins have several potential benefits including its antioxidant, anti-inflammatory, and anti-thrombogenic properties that may prevent the worsening of atherosclerosis in high-risk women. Nevertheless, most studies on statins and teratogenicity have a limited sample size and the effects of long-term statin use on fetal and neonatal health remain unknown. Not all statins may be safe and pravastatin's cholesterol-lowering properties may be too limited to provide much maternal benefit in pregnancy. While emerging evidence supports the use of pravastatin in pregnancy, we need to better assess the risk of early cardiovascular disease and acute progression of atherosclerosis before and during pregnancy to better understand the risks and benefits of statin use.

Drug development research in pregnant and lactating women

Pregnant and lactating women are considered "therapeutic orphans" because they generally have been excluded from clinical drug research and the drug development process owing to legal, ethical, and safety concerns. Most medications prescribed for pregnant and lactating women are used "off-label" because most of the clinical approved medications do not have appropriate drug labeling information for pregnant and lactating women. Medications that lack human safety data on use during pregnancy and lactation may pose potential risks for adverse effects in pregnant and lactating women as well as risks of teratogenic effects to their unborn and newborn babies. Federal policy requiring the inclusion of women in clinical research and trials led to considerable changes in research design and practice. Despite more women being included in clinical research and trials, the inclusion of pregnant and lactating women in drug research and clinical trials remains limited. A recent revision to the "Common Rule" that removed pregnant women from the classification as a "vulnerable" population may change the culture of drug research and drug development in pregnant and lactating women. This review article provides an overview of medications studied by the Obstetric-Fetal Pharmacology Research Units Network and Centers and describes the challenges in current obstetrical pharmacology research and alternative strategies for future research in precision therapeutics in pregnant and lactating women. Implementation of the recommendations of the Task Force on Research Specific to Pregnant Women and Lactating Women can provide legislative requirements and opportunities for research focused on pregnant and lactating women.

Ethical issues in therapeutic use and research in pregnant and breastfeeding women

Pregnant or potentially pregnant women have historically been excluded from clinical trials of new medications. However, it is increasingly recognised that it is imperative to generate evidence from the population in whom the drugs are likely to be used to inform safe, evidence-based shared clinical decision making. Reluctance by researchers and regulators to perform such studies often relates to concerns about risk, particularly to the foetus. However, this must be offset against the risk of untreated disease or using a drug in pregnancy where safety, efficacy and dosing information are not known. This review summarises the historical perspective, and the ethical and legal frameworks that inform the conduct of such research, then highlights examples of innovative practice that have enabled high quality, ethical research to proceed to inform the evidence-based use of medication in pregnancy.

Regulatory Considerations for the Mother, Fetus and Neonate in Fetal Pharmacology Modeling

The regulatory framework for considering the fetal effects of new drugs is limited. This is partially due to the fact that pediatric regulations (21 CFR subpart D) do not apply to the fetus, and only US Health and Human Service (HHS) regulations apply to the fetus. The HHS regulation 45 CFR Part 46 Subpart B limits research approvable by an institutional review board to research where the risk to the fetus is minimal unless the research holds out the prospect of a direct benefit to the fetus or the pregnant woman (45 CFR 46.204). Research that does not meet these requirements, but presents an opportunity to understand, prevent, or alleviate a serious problem affecting the health of pregnant women, fetuses, or neonates, may be permitted by the Secretary of the HHS after expert panel consultation and opportunity for public review and comment (45 CFR 46.407). If the product is regulated by the US Food and Drug Administration (FDA), FDA may get involved in the review process. The FDA does however have a Reviewer Guidance on Evaluating the Risks of Drug Exposure in Human Pregnancies from 2005 and this guidance does discuss the intensity of drug exposure. Estimation of that exposure using physiologically based pharmacokinetic (PBPK) modeling has been suggested by some investigators. Given that drug exposure during pregnancy will impact the fetus, a number of new guidances in the last 2 years also address inclusion of pregnant women in clinical drug trials. Therefore, the drug-specific information on fetal pharmacology will increase dramatically in the next decade due to interest in drugs administered in pregnancy and with the assistance of model-informed drug development.

Pravastatin for preeclampsia: From animal to human

Preeclampsia is characterized by the emergence of hypertension and proteinuria after 20 weeks of pregnancy, and it threatens both maternal and fetal lives if it proceeds unabated. Despite numerous studies, thus far the only fundamental therapy for preeclampsia is termination of pregnancy, leading to preterm birth. Furthermore, preeclamptic women are reported to be at risk for cardiovascular diseases for 10 years after delivery. Therefore, preventative and therapeutic strategies for preeclampsia are required. Recently, statins have been reported to improve the regeneration of vascular endothelium, and pravastatin has attracted attention as a potential preventative or therapeutic candidate for preeclampsia. Pravastatin has been demonstrated to have preventative effects in preeclampsia model mice, and a large volume of human data from pregnant women taking statins supports the safety of these drugs. Moreover, small clinical trials have reported that pravastatin has strong preventative or therapeutic effects on preeclampsia and it has the potential to improve the prognosis of pregnant women, fetuses and neonates affected by this condition.

Challenges in conducting clinical research studies in pregnant women

Maternal mortality and morbidity continue to rise in the United States. Despite these trends there are limited novel interventions to investigate and improve these metrics, partly due to research protocol limitations which restrict participation of pregnant women. Inclusion of pregnant women in research studies is integral to the process of obtaining important information regarding the safety and efficacy of therapeutics or interventions to improve maternal health and pregnancy outcomes. While significant changes in research practices have resulted in an increase of female participants, there remains a paucity of research trials directly targeting pregnant and lactating women. This article provides an overview of issues surrounding inclusion of pregnant or breastfeeding women in research studies, and includes historical perspectives, navigating concerns over safety profile, considerations for appropriate development, and future perspectives.

Lipids and Women's Health: Recent Updates and Implications for Practice

The obstetrician/gynecologist frequently serves as the primary care physician for women. Specialty-specific guidelines vary in screening recommendations for lipid disorders; women's health practitioners often follow recommendations to screen at age 45 in the absence of other risk factors. However, 2013 American College of Cardiology/American Heart Association cholesterol guidelines recommend screening at age 21 to capture those at risk of cardiovascular disease and allow for early intervention with lifestyle and, in the most severe cases, evidence-based statins. We discuss the care of women who primarily benefit from screening: those with familial hypercholesterolemia (FH), those with the metabolic syndrome (MetS) or polycystic ovary syndrome, and those with hypertriglyceridemia. Those with FH have elevated low-density lipoprotein cholesterol from birth and a propensity for premature coronary heart disease. Early recognition of FH can allow risk-reducing interventions, as well as identification of additional affected relatives. Early detection of metabolic variables, such as in the MetS and hypertriglyceridemia, can lead to an enhanced focus on physical activity and heart-healthy diet. Finally, we discuss a practical approach to lipid management and review concerns regarding drug safety. Our objective is to provide a current overview of cardiovascular risk factor optimization that women's health practitioners can use in identifying and/or treating patients at risk for cardiovascular disease and diabetes.

Aspirin Effect on Adverse Pregnancy Outcomes Associated With Stage 1 Hypertension in a High-Risk Cohort

Recently, the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines revised the recommendations for diagnosis of chronic hypertension. The new classification system includes a diagnosis of stage 1 hypertension in adults with blood pressures 130 to 139/80 to 89 mm Hg. We sought to compare outcomes among women at high risk for preeclampsia with stage 1 hypertension and assessed whether women with stage 1 hypertension had benefit from aspirin treatment compared with high-risk normotensive women. We performed a secondary analysis of the high-risk aspirin trial and included women with prior preeclampsia or diabetes mellitus. Among these women, 827 (81%) were classified as normotensive, whereas 193 (19%) were classified as stage 1 hypertensive. Among women receiving placebo, preeclampsia occurred significantly more often in women with stage 1 hypertension compared with normotensive high-risk women after adjustment for maternal age and body mass index (39.1% versus 15.1%; risk ratio, 2.49; 95% confidence interval, 1.74-3.55). Further, women with stage 1 hypertension had a significant risk reduction related to aspirin prophylaxis (risk ratio, 0.61; 95% confidence interval, 0.39-0.94) that was not seen in normotensive high-risk women (risk ratio, 0.97; 95% confidence interval, 0.70-1.34). Application of the American College of Cardiology/American Heart Association guidelines in a high-risk population demonstrates that in the setting of other risk factors, the presence of stage 1 hypertension is associated with a significantly increased risk of preeclampsia when compared with high-risk normotensive women. These findings emphasize the importance of recognition of stage 1 hypertension as an additive risk factor in women at high risk for preeclampsia and the benefit of aspirin.

Dyslipidemia in Pregnancy

"Recent studies have revealed evidence that poorly controlled cholesterol, triglycerides, and their metabolites during pregnancy may be associated with cardiometabolic dysfunction and have significant detrimental fetal and maternal vascular consequences. Cardiometabolic dysfunction during pregnancy may not only contribute to long-term effects of the mother and child's vascular health but also potentially create cardiovascular risk for generational offspring. This article provides updates on this rapidly expanding and multifaceted topic and reviews new insight regarding why recognition of this disordered maternal cholesterol and triglyceride metabolism is likely to have long-term effect on the increasing atherosclerotic burden of the burgeoning population."

Preeclampsia and Pregnancy-Related Hypertensive Disorders

Our understanding of hypertension during pregnancy and, in particular, preeclampsia has changed dramatically over the last decade. During the last year (2014–2015), several articles published in Hypertension have provided important insights into the pathogenesis of preeclampsia and its related complications.1–38 In addition, Hypertension also published some key research communications that translated important basic science observations into the clinic. Some of these articles are briefly discussed, highlighting their significance to our understanding of the mechanism of the disease, to predict the disease and to treat or prevent hypertension during pregnancy and other preeclampsia-related complications.

Epidemiology of medications use in pregnancy

The use of prescribed and over-the-counter medications in pregnancy is on the rise. Many women become pregnant at an older age and with preexisting medical conditions that require pharmacotherapy. In addition, pregnancy is associated with profound changes in the physiology of virtually every organ in the body, which affect medications' pharmacokinetics and pharmacodynamics. Despite all of these, pregnant women are still considered therapeutic orphans, as the majority of current therapeutics were never studied in pregnancy. The goals of this review are to synthesize the available information regarding the epidemiology of medications use and the state of drug research in pregnancy, in an effort to highlight the need for pharmacologic research in pregnancy.

Special population considerations and regulatory affairs for clinical research

Special populations, including women (non-pregnant and pregnant), pediatrics, and the elderly, require additional consideration with regard to clinical research. There are very specific regulatory laws, which protect these special populations, that need to be understood and adhered to in order to perform clinical research. This review provides a broad overview of some of the physiological differences in special populations and discusses how these differences may affect study design and regulatory considerations. These various special populations, with respect to regulatory affairs, are clearly defined within the Code of Federal Regulations. The definition of "special population" exists to provide enhanced awareness of their vulnerabilities, thereby allowing the creation of regulatory guidance aimed to decrease injury or outright harm. Currently, progress is being made to be more inclusive of special populations in clinical trials. This reflects changing attitudes towards drug information, with it being more representative of those patients that will ultimately be prescribed or exposed to the therapy. However, all research undertaken in these populations should be performed in a manner that ensures all protections of each participant are upheld.

Heme oxygenase-1 is critically involved in placentation, spiral artery remodeling, and blood pressure regulation during murine pregnancy

The onset of pregnancy implies the appearance of a new organ, the placenta. One main function of the placenta is to supply oxygen to the fetus via hemoproteins. In this review, we highlight the importance of the enzyme heme oxygenase-1 (HO-1) for pregnancy to be established and maintained. HO-1 expression is pivotal to promote placental function and fetal development, thus determining the success of pregnancy. The deletion of the gene Hmox1 in mice leads to inadequate remodeling of spiral arteries and suboptimal placentation followed by intrauterine growth restriction (IUGR) and fetal lethality. A partial Hmox1 deletion leads to IUGR as well, with heterozygote and wild-type fetuses being born, but Hmox1 (-/-) significantly below the expected Mendelian rate. This strong phenotype is associated with diminished number of pregnancy-protective uterine natural killer (uNK) cells. Pregnant heterozygote females develop gestational hypertension. The protective HO-1 effects on placentation and fetal growth can be mimicked by the exogenous administration of carbon monoxide (CO), a product of heme catalyzed by HO-1. CO application promotes the in situ proliferation of uNK cells, restores placentation and fetal growth, while normalizing blood pressure. Similarly, HO-1 inhibition provokes hypertension in pregnant rats. The HO-1/CO axis plays a pivotal role in sustaining pregnancy and aids in the understanding of the biology of pregnancy and reveals a promising therapeutic application in the treatment of pregnancy complications.