Related Experiment Video
Updated: Jun 28, 2025
Development of a Preclinical Inhalation Model to Test Vaporized Cannabis Distillates
Published on: May 30, 2025
Physiologically based modeling reveals different risk of respiratory depression after fentanyl overdose between
Shilpa Chakravartula1, Bradlee Thrasher1, John Mann1
1Division of Applied Regulatory Science, Office of Clinical Pharmacology, Office of Translational Sciences, Center for Drug Evaluation and Research, Food and Drug Administration, Silver Spring, Maryland, USA.
Insights
Children may face higher risks of opioid-induced respiratory depression and brain hypoxia in community settings. This is due to their higher oxygen demand and reduced cerebrovascular reactivity, even at the same fentanyl concentrations as adults.
Area of Science:
- Pharmacology
- Pediatric Medicine
- Translational Science
Background:
- Pediatric mortality from opioids is rising, yet research on dose-dependent respiratory depression in children is limited.
- Opioid-associated respiratory depression is the primary cause of death in pediatric opioid overdose cases.
- Existing models lack pediatric-specific pharmacokinetic, pharmacodynamic, and physiological considerations.
Purpose of the Study:
- To extend a translational model for opioid-induced respiratory depression to pediatric populations.
- To investigate age-dependent factors influencing opioid effects in children compared to adults.
- To identify potential differences in opioid risk between perioperative and community settings for children.
Main Methods:
- Incorporated age-dependent pharmacokinetic, pharmacodynamic, and physiological variables into a pre-existing translational model.
- Modeled respiratory depression endpoints like minute ventilation and blood CO2 tension.
- Compared model predictions for pediatric and adult populations under various clinical scenarios.
Main Results:
- The model confirmed similar respiratory depression risks in children and adults at equivalent plasma fentanyl concentrations when using ventilation and CO2 endpoints.
- Perioperative settings with mechanical ventilation and oxygen mask potential oxygen-related consequences of respiratory depression.
- In community settings, children may be more vulnerable to hypoxemia and brain hypoxia due to higher oxygen demand and reduced cerebrovascular reactivity.
Conclusions:
- Pediatric-specific factors, including higher oxygen demand and altered cerebrovascular reactivity, increase susceptibility to severe hypoxemia in community settings.
- These factors are critical for developing effective intervention strategies against pediatric opioid overdose.
- The model highlights the need to consider age-dependent physiological differences when assessing opioid risks in children.
Abstract:
Despite a rapid increase in pediatric mortality rate from prescription and illicit opioids, there is limited research on the dose-dependent impact of opioids on respiratory depression in children, the leading cause of opioid-associated death. In this article, we extend a previously developed translational model to cover pediatric populations by incorporating age-dependent pharmacokinetic, pharmacodynamic, and physiological changes compared to adults. Our model reproduced previous perioperative clinical findings that adults and children have similar risk of respiratory depression at the same plasma fentanyl concentration when specific endpoints (minute ventilation, CO2 tension in the blood) were used. However, our model points to a potential caveat that, in a perioperative setting, routine use of mechanical ventilation and supplemental oxygen maintained the blood and tissue oxygen partial pressures in patients and prevented the use of oxygen-related endpoints to evaluate the consequences of respiratory depression. In a community setting when such oxygenation procedures are not immediately available, our model suggests that the higher oxygen demand and reduced cerebrovascular reactivity could make children more susceptible to severe hypoxemia and brain hypoxia, even with the same plasma fentanyl concentration as adults. Our work indicates that when developing intervention strategies to protect children from opioid overdose in a community setting, these pediatric-specific factors may need to be considered.
Related Concept Videos
01:15Opioid Analgesics: Synthetic and Semisynthetic Opioids
01:26Pharmacokinetic Models: Comparison and Selection Criterion
Physiological models take a detailed approach by considering specific molecular processes. They can predict drug distribution, metabolism, and elimination changes, providing a comprehensive understanding of how drugs interact with the body.
01:20Opioid Analgesics: Morphine and Other Natural Cogeners
01:20Pharmacokinetic Models: Overview
There are three primary types of models: empirical, compartment, and physiological. Empirical models, with minimal...
00:57Physiological Pharmacokinetic Models: Blood Flow-Limited Versus Diffusion-Limited Models
01:21Factors Affecting Drug Response: Overview