A Tribute to the Pioneers of Fetal Pharmacology.

Clinical pharmacology is a branch of the field of pharmacology that evolved following the recognition that the nature, duration, and intensity of drug action depend on both the intrinsic properties of the drug and an interaction with the host to whom the drug is given. Advances in drug development have placed highly specific and extremely potent therapeutic agents in the marketplace. While these advances have progressed rapidly in adult medicine, pediatric clinical pharmacology has not kept pace and until very recently has lagged behind the research and attention paid to the proper use of therapeutic and diagnostic drugs in adults. Recognition that advances in the science of developmental pharmacology and pediatric clinical pharmacology were essential in the development of new drugs to treat children came in the 1950s and 1960s mostly through the work of 2 pioneering scientists in fetal and perinatal clinical pharmacology, Drs Sumner Yaffe and Bernard Mirkin. Here we pay a tribute to these most influential pioneers in the United States who were instrumental in paving the path for advancing the field of fetal and perinatal pharmacology concepts and their incorporation into pediatric drug development programs.

What Could the Future of Safety Monitoring Look Like?

Like much of the clinical research and health care provider enterprise, the data capture and archiving for harm, probability of harm, and impact of intervention-related events is fragmented, inconsistent, and lacks standards to perform the types of operations that could inform researchers, practitioners, and patients in a timely way of actions and policies. The entire system of assessments, terminology, data formats and structure, analyses, and dissemination would benefit from changes based on adherence to a process framework of detect, describe, analyze, and react in the context of recognizing the multiple pathways and factors that lead to any specific outcome or series of outcomes. Existing tools, if properly applied, can form the basis for the next generation of data systems, processes, analyses, and sharing to address most of the current challenges.

Research Gaps in Primary Pediatric Hypertension.

Hypertension affects >40% of the US population and is a major contributor to cardiovascular-related morbidity and mortality. Although less common among children and adolescents, hypertension affects 1% to 5% of all youth. The 2017 Clinical Practice Guideline for the Diagnosis and Management of High Blood Pressure in Children and Adolescents provided updates and strategies regarding the diagnosis and management of hypertension in youth. Despite this important information, many gaps in knowledge remain, such as the etiology, prevalence, and trends of hypertension; the utility and practicality of ambulatory blood pressure monitoring; practical goals for lifestyle modification that are generalizable; the long-term end-organ impacts of hypertension in youth; and the long-term safety and efficacy of antihypertensive therapy in youth. The Eunice Kennedy Shriver National Institute of Child Health and Human Development, in collaboration with the National Heart, Lung, and Blood Institute and the US Food and Drug Administration, sponsored a workshop of experts to discuss the current state of childhood primary hypertension. We highlight the results of that workshop and aim to (1) provide an overview of current practices related to the diagnosis, management, and treatment of primary pediatric hypertension; (2) identify related research gaps; and (3) propose ways to address existing research gaps.

Acute Responses to Diuretic Therapy in Extremely Low Gestational Age Newborns: Results from the Prematurity and Respiratory Outcomes Program Cohort Study.

OBJECTIVE: To determine if daily respiratory status improved more in extremely low gestational age (GA) premature infants after diuretic exposure compared with those not exposed in modern neonatal intensive care units. STUDY DESIGN: The Prematurity and Respiratory Outcomes Program (PROP) was a multicenter observational cohort study of 835 extremely premature infants, GAs of 230/7-286/7 weeks, enrolled in the first week of life from 13 US tertiary neonatal intensive care units. We analyzed the PROP study daily medication and respiratory support records of infants ≤34 weeks postmenstrual age. We determined whether there was a temporal association between the administration of diuretics and an acute change in respiratory status in premature infants in the neonatal intensive care unit, using an ordered categorical ranking of respiratory status. RESULTS: Infants in the diuretic exposed group of PROP were of lower mean GA and lower mean birth weight (P < .0001). Compared with infants unexposed to diuretics, the probability (adjusted for infant characteristics including GA, birth weight, sex, and respiratory status before receiving diuretics) that the exposed infants were on a higher level of respiratory support was significantly greater (OR, >1) for each day after the initial day of diuretic exposure. CONCLUSIONS: Our analysis did not support the ability of diuretics to substantially improve the extremely premature infant's respiratory status. Further study of both safety and efficacy of diuretics in this setting are warranted. TRIAL REGISTRATION: Clinicaltrials.gov: NCT01435187.

Inclusion of pregnant and breastfeeding women in research - efforts and initiatives.

Pregnant and breastfeeding women have been rendered therapeutic orphans as they have been historically excluded from clinical trials. Labelling for most approved drugs does not provide information about safety and efficacy during pregnancy. This lack of data is mainly due to ethico-legal challenges that have remained entrenched in the post-diethylstilbestrol and thalidomide era, and that have led to pregnancy being viewed in the clinical trial setting primarily through a pharmacovigilance lens. Policy considerations that encourage and/or require the inclusion of pregnant or lactating women in clinical trials may address the current lack of available information. However, there are additional pragmatic strategies, such the employment of pharmacometric tools and the introduction of innovative clinical trial designs, which could improve knowledge about the safety and efficacy of medication use during pregnancy and lactation. This paper provides a broad overview of the pharmacoepidemiology of drugs used during pregnancy and lactation, and offers recommendations for regulators and researchers in academia and industry to increase the available pharmacokinetic and -dynamic understanding of medication use in pregnancy.

Development of Drug Therapies for Newborns and Children: The Scientific and Regulatory Imperatives.

Pediatric legislation has generated information about the efficacy, safety, and dosing of more than 600 products in children. Extrapolation of adult efficacy data has been an integral part of pediatric drug development. Advances in our understanding of physiology and pharmacology have improved the approach to pediatric dose selection. However, a high percentage of pediatric trials do not meet their primary efficacy endpoint. Delays in initiating completing pediatric studies persist. This article describes these advances and provides innovative approaches to optimize pediatric drug development.

Enrollment of Neonates in More Than One Clinical Trial.

Because the highest rates of morbidity and mortality in neonates are seen in those born at <32 weeks' gestation, this group has the most urgent need for novel therapies to improve survival and outcome. Legislative efforts in the United States and Europe have attempted to address this issue by requiring the study of drugs, biological and nutritional products, devices, and other therapies in this population through a combination of high-quality regulatory and clinical trials, quality improvement initiatives, and observational studies. Because there are relatively small numbers of very preterm neonates born each year in any 1 country or continent, and because a significant number of clinical trials are recruiting at any 1 time, a neonate may meet enrollment criteria for >1 clinical trial. Neonatal units that have the infrastructure and resources to engage in research frequently face the question of whether it is permissible to enroll a neonate in >1 trial. This article examines the pertinent scientific, ethical, regulatory, and industry issues that should be taken into account when considering enrolling neonates in multiple clinical studies.

Pediatric Multiple Organ Dysfunction Syndrome: Promising Therapies.

OBJECTIVE: To describe the state of the science, identify knowledge gaps, and offer potential future research questions regarding promising therapies for children with multiple organ dysfunction syndrome presented during the Eunice Kennedy Shriver National Institute of Child Health and Human Development Workshop on Pediatric Multiple Organ Dysfunction Syndrome (March 26-27, 2015). DATA SOURCES: Literature review, research data, and expert opinion. STUDY SELECTION: Not applicable. DATA EXTRACTION: Moderated by an expert from the field, issues relevant to the association of multiple organ dysfunction syndrome with a variety of conditions were presented, discussed, and debated with a focus on identifying knowledge gaps and research priorities. DATA SYNTHESIS: Summary of presentations and discussion supported and supplemented by relevant literature. CONCLUSIONS: Among critically ill children, multiple organ dysfunction syndrome is relatively common and associated with significant morbidity and mortality. For outcomes to improve, effective therapies aimed at preventing and treating this condition must be discovered and rigorously evaluated. In this article, a number of potential opportunities to enhance current care are highlighted including the need for a better understanding of the pharmacokinetics and pharmacodynamics of medications, the effect of early and optimized nutrition, and the impact of effective glucose control in the setting of multiple organ dysfunction syndrome. Additionally, a handful of the promising therapies either currently being implemented or developed are described. These include extracorporeal therapies, anticytokine therapies, antitoxin treatments, antioxidant approaches, and multiple forms of exogenous steroids. For the field to advance, promising therapies and other therapies must be assessed in rigorous manner and implemented accordingly.

Review of the Best Pharmaceuticals for Children Act and the Pediatric Research Equity Act: What can the obstetric community learn from the pediatric experience?

Children have been called therapeutic orphans as they have been excluded from drug research and new drug development resulting in the lack of proper labels for majority of the drugs for pediatric use. The Best Pharmaceuticals for Children Act (BPCA) and the Pediatric Research Equity Act (PREA) are two legislative mandates to improve pediatric drug labeling. The BPCA legislation authorizes the National Institutes of Health (NIH) to implement research programs through funding clinical trials to study off-patent drugs in pediatric population. Obstetric pharmacology research gaps are in many ways similar to those in pediatrics, including off-label use of common medications, and lack of knowledge of appropriate dosing, safety, and efficacy of drugs. Much research is needed to define mechanisms of disease and drug actions in pregnant women to fill the knowledge gaps.

A hemodynamic model to guide blood pressure control during deliberate hypotension with sodium nitroprusside in children.

Sodium nitroprusside (SNP) has been widely used to control blood pressure in infants and children. The goals of this analysis were to develop models that describe the hemodynamic response to SNP dosing in pediatric patients; examine sources of variation in dose-response, defining age, and size dependencies; and determine vulnerable populations or patient subtypes that may elicit dosing modifications. A multi-center, randomized, double-blinded, parallel-group, dose-ranging, effect-controlled study, followed by an open-label dose titration of an intravenous infusion of SNP was undertaken in 203 pediatric subjects, who required deliberate hypotension or controlled normotension during anesthesia. A total of 3464 MAP measurements collected from 202 patients during the study's blinded phase, including baseline measurements up to 6 min prior to the blinded were available for analysis. A population K-PD model was developed with a one-compartment model assumed for SNP. Size differences in CL and V of the effect compartment were described using theory-based allometry. An inhibitory sigmoidal Emax model was used to describe the effect of SNP. A power function of age was used to describe age-related differences in baseline MAP. A mixture model of two groups with low and high EC50 was used to explain variability in MAP response. Change in MAP was characterized by a linear disease progression slope during the blinded phase. In the final population model, CL and V increased with weight, and baseline MAP increased with age. The effect compartment half-life of SNP was 13.4 min. The infusion rate producing 50% of Emax (ER50) at steady state for high EC50, was 0.34 µg/kg/min and for low EC50 0.103 µg/kg/min. The K-PD model well-describes initial dosing of SNP under controlled circumstances; model-based dosing guidance agrees with current practice. An initial titration strategy supported via algorithm-based feedback should improve maintenance of target MAP.

Evaluation of sodium nitroprusside for controlled hypotension in children during surgery.

PURPOSE: (1) To define the onset and offset of the blood-pressure-lowering effects of sodium nitroprusside (SNP) for use in developing instructions for dose titration in children undergoing a surgical or medical procedure, and (2) to assess the safety of SNP administration in pediatric patients requiring controlled reduction of blood pressure. METHODS: We conducted a randomized, double-blind, parallel-group, dose-ranging, effect-controlled, multicenter study of intravenous (IV) infusions of SNP in pediatric patients <17 years, who required controlled hypotension for at least 2 h while undergoing a surgical or medical procedure. A blinded SNP dose of 0.3, 1, 2, or 3 µg/kg/min was infused for 30 min, followed by open-label administration for at least 90 min. Both infusions were titrated to effect. RESULTS: The final intent-to-treat group comprised 203 patients. Significant reductions in mean arterial pressure (MAP) from baseline were observed for all four doses at 20 and 25 min after the start of infusion (p ≤ 0.009 and p ≤ 0.010 for each time, respectively). Overall, 98.5% of the patients achieved the target MAP; 72.9% first achieved the target MAP during the blinded infusion. The mean infusion rate at target MAP was 1.07 µg/kg/min. CONCLUSION: We determined that 0.3 µg/kg/m is a reasonable starting dose for SNP in pediatric patients requiring controlled hypotension. The infusion rate can then be increased to achieve the desired reduction in blood pressure. On the basis of our results, we found an average infusion rate of 1 µg/kg/min might be appropriate. Of note, no cyanide toxicity was reported, and no measureable cyanide levels were detected in any blood samples obtained during the study. http://clinicaltrials.gov/show/NCT00135668.

Population pharmacokinetics of oseltamivir in non-pregnant and pregnant women.

AIMS: Physiological changes in pregnancy are expected to alter the pharmacokinetics of various drugs. The objective of this study was to evaluate systematically the pharmacokinetics of oseltamivir (OS), a drug used in the treatment of influenza during pregnancy. METHODS: A multicentre steady-state pharmacokinetic study of OS was performed in 35 non-pregnant and 29 pregnant women. Plasma concentration-time profiles were analyzed using both non-compartmental and population pharmacokinetic modelling (pop PK) and simulation approaches. A one compartment population pharmacokinetic model with first order absorption and elimination adequately described the pharmacokinetics of OS. RESULTS: The systemic exposure of oseltamivir carboxylate (OC, active metabolite of OS) was reduced approximately 30 (19-36)% (P < 0.001) in pregnant women. Pregnancy significantly (P < 0.001) influenced the clearance (CL/F) and volume of distribution (V/F) of OC. Both non-compartmental and population pharmacokinetic approaches documented approximately 45 (23-62)% increase in clearance (CL/F) of OC during pregnancy. CONCLUSION: Based on the decrease in exposure of the active metabolite, the currently recommended doses of OS may need to be increased modestly in pregnant women in order to achieve comparable exposure with that of non-pregnant women.

Applying Regulatory Science to Develop Safe and Effective Medicines for Neonates: Report of the US Food and Drug Administration First Annual Neonatal Scientific Workshop, October 28-29, 2014.

The First Annual Neonatal Scientific Workshop focused on the needs of the neonate by addressing the basic question: what information is required to inform decision making both at the regulatory level and at the bedside? Priority therapeutic areas include neonatal lung, brain, and gastrointestinal injury, retinopathy of prematurity, sepsis, and neonatal abstinence syndrome. Scientific progress in these therapeutic areas, regulatory standards, and the acceptable design and conduct of clinical trials must be aligned. This report will review potential approaches to enhancing neonatal drug development.

Meeting the demand for pediatric clinical trials.

High-quality, cost-effective pediatric clinical trials require a robust research and regulatory infrastructure and a properly trained workforce.

A report from the pediatric formulations task force: perspectives on the state of child-friendly oral dosage forms.

Despite the fact that a significant percentage of the population is unable to swallow tablets and capsules, these dosage forms continue to be the default standard. These oral formulations fail many patients, especially children, because of large tablet or capsule size, poor palatability, and lack of correct dosage strength. The clinical result is often lack of adherence and therapeutic failure. The American Association of Pharmaceutical Scientists formed a Pediatric Formulations Task Force, consisting of members with various areas of expertise including pediatrics, formulation development, clinical pharmacology, and regulatory science, in order to identify pediatric, manufacturing, and regulatory issues and areas of needed research and regulatory guidance. Dosage form and palatability standards for all pediatric ages, relative bioavailability requirements, and small batch manufacturing capabilities and creation of a viable economic model were identified as particular needs. This assessment is considered an important first step for a task force seeking creative approaches to providing more appropriate oral formulations for children.

Comparison of a new cobinamide-based method to a standard laboratory method for measuring cyanide in human blood.

Most hospital laboratories do not measure blood cyanide concentrations, and samples must be sent to reference laboratories. A simple method is needed for measuring cyanide in hospitals. The authors previously developed a method to quantify cyanide based on the high binding affinity of the vitamin B12 analog, cobinamide, for cyanide and a major spectral change observed for cyanide-bound cobinamide. This method is now validated in human blood, and the findings include a mean inter-assay accuracy of 99.1%, precision of 8.75% and a lower limit of quantification of 3.27 µM cyanide. The method was applied to blood samples from children treated with sodium nitroprusside and it yielded measurable results in 88 of 172 samples (51%), whereas the reference laboratory yielded results in only 19 samples (11%). In all 19 samples, the cobinamide-based method also yielded measurable results. The two methods showed reasonable agreement when analyzed by linear regression, but not when analyzed by a standard error of the estimate or paired t-test. Differences in results between the two methods may be because samples were assayed at different times on different sample types. The cobinamide-based method is applicable to human blood, and can be used in hospital laboratories and emergency rooms.

Eunice Kennedy Shriver National Institute of Child Health and Human Development Pediatrics Formulation Initiative: proceedings from the Second Workshop on Pediatric Formulations.

BACKGROUND: The Eunice Kennedy Shriver National Institute of Child Health and Human Development of the National Institutes of Health (NIH) organized a workshop held in November 2011 to address knowledge gaps that limit the availability of adequate pediatric formulations. This workshop was used as a means to identify the types of research innovations needed and to stimulate research efforts designed to improve the availability of pediatric formulations and the technologies required to make these formulations. METHODS: Information for this article was gathered from the proceedings of the Second US PFI Workshop sponsored by the Eunice Kennedy Shriver National Institute of Child Health and Human Development in Bethesda, Maryland, on November 1 and 2, 2011, as well as from post-workshop discussions. The workshop preparation began with formation of 4 working groups: Biopharmaceutics, Biopharmaceutics Classification System (BCS), New Technology and Drug Delivery Systems, and Taste and Flavor. RESULTS: The recommendations of the 4 working groups will form the basis for the development of a blueprint to guide future research efforts. The pediatric-specific problems identified include the heterogeneity of the population, the small size of the pediatric drug market, the limited number of new formulations for the large number of off-patent and unlabeled drugs, and the lack of universal agreement on how to define appropriate formulations for different ages and stages of development. There was consensus on the need to develop a universal technology platform for flexible pediatric dosage forms, transforming an empirical process into a science-based platform. A number of problems affect the availability of drugs in the developing world. Age-appropriate solid oral pediatric medicines for common diseases can have a global impact. Success on a global scale depends on the commitment of policy makers, regulators, scientists, pharmaceutical companies, sponsors, government, and research foundations to address gaps in knowledge and solve public health issues related to the availability of formulations in the developing world. CONCLUSIONS: Solutions to the worldwide lack of appropriate pediatric formulations will require the development of a road map and the commitment of policy makers, regulators, scientists, pharmaceutical sponsors, academic institutions, governments, and research foundations. The development of a universal, cost-effective platform using existing or developing innovative technology that produces flexible pediatric dosage forms remains an important but elusive goal.

Pharmacology and placental transport of 17-hydroxyprogesterone caproate in singleton gestation.

OBJECTIVE: The purpose of this study was to estimate pharmacokinetic parameters and to evaluate placental transport of 17-hydroxyprogesterone caproate (17-OHPC) in singleton gestation. STUDY DESIGN: Sixty-one women who received weekly injections of 17-OHPC underwent 2 pharmacokinetic studies at 20 + 0 to 24 + 6 weeks' gestation (study 1) and 31 + 0 to 34 + 6 weeks' gestation (study 2); daily blood samples were obtained between injections. In 18 women, blood samples were obtained over a 28-day period beyond the last injection (extended study). Maternal and/or cord blood were obtained at delivery. RESULTS: The half-life (median ± SD) of 17-OHPC was 16.2 ± 6 days. Concentrations of 17-OHPC were higher during study 2 than during study 1. Body mass index affected maternal 17-OHPC concentrations. Cord:maternal 17-OHPC concentration ratios averaged 0.2; 17-OHPC was detectible in cord plasma 44 days after the last maternal injection. CONCLUSION: The apparent half-life of 17-OHPC is long, and pharmacokinetic parameters vary widely between subjects and are affected by maternal body mass index. The drug crosses the placental barrier.