Pharmacotherapy research landscape and knowledge gaps of opioids in maternal and pediatric populations

Abstract

The use and misuse of opioids has surged in the past decade, with nearly half of the users being female. Although opioid use is lower among pregnant women, trends mirror the general population. While pediatric exposures largely occur through prescriptions. This review presents a novel landscape analysis of pharmacology knowledge gaps in opioids in the maternal and pediatric populations. We queried PubMed for studies on 27 opioids, focusing on pharmacokinetics (PK), and pharmacoepidemiology (PE) or clinical trials (CT) in maternal and pediatric populations. English-language publications were included, and data were synthesized to identify gaps. Additionally, MarketScan claims data and United States Food and Drug Administration (FDA) drug labels were analyzed to compare scientific evidence, opioid prescriptions/orders, and FDA recommendations. Morphine, fentanyl, methadone, and buprenorphine are the most researched opioids in PK and PE/CT literature in both populations, but hydrocodone, oxycodone, and codeine are the most prescribed. Nine opioids lack FDA labels, and four of the 18 labeled drugs lack any human data. Hydrocodone, oxycodone, and codeine labels include lactation-focused PK information, with some pediatric clinical data for the latter two. Seven opioids lack PK and PE/CT studies in the maternal population, and PK research is absent for seven opioids, and PE/CT data is lacking for eight opioids in the pediatric population. PK studies often focus on labor, delivery, and lactation accompanied by neonatal data, whereas pregnancy research mainly occurs in PE studies. In pediatric populations, study types are evenly distributed among children, but PE studies focus more on adolescents. Drug concentration is the most reported parameter in PK studies, and neonatal opioid withdrawal syndrome (NOWS) is a key outcome in both PK and PE studies. NOWS is also researched more using real-world data, whereas neurodevelopmental outcomes are often captured in prospective observational studies. There is substantial disparity between the most commonly researched and prescribed opioids. In particular, the opioid pharmacology knowledge gaps are larger in pregnant women and for the highly prescribed opioids hydrocodone and oxycodone. The limited human data in FDA labels underscores the need for additional studies. Studies using real-world data can potentially help address these gaps.