Exploring the Impact of Delta-9-Tetrahydrocannabinol (THC) on Driving Performance Using A Physiologically Based Pharmacokinetic/Pharmacodynamic Model
Poster Number
10A
Faculty Mentor Name
Zhu Zhou
Format
Poster Presentation
Research or Creativity Area
Pharmacy
Abstract
Delta-9-tetrahydrocannabinol (THC) is the primary cannabinoid responsible for the psychoactive effects of Cannabis (family Cannabaceae). The increasing use of cannabis for both recreational and therapeutic applications has brought attention to THC. Impairment in driving performance is one of the important psychoactive effects that may lead to motor vehicle accidents. By 2023, THC-positive drivers represented approximately 32% of drivers tested for drugs in fatal crashes. Therefore, it is critical to understand the dose-exposure-response relationship between THC and the degree of driving performance impairment.
Purpose
This study aimed to develop and verify a physiologically based pharmacokinetic/pharmacodynamic (PBPK/PD) model to understand the relationship between THC dosing and driving performance impairment. The changes in Standard Deviation of Lateral Position (SDLP) were used as an indicator of driving performance. SDLP is a measure of vehicle control and driving safety; a larger SDLP indicates a greater degree of impairment in driving performance. The PD modeling was integrated with our previously developed and published PBPK model for THC using Simcyp™ (Version 25). Parameters from a published linear model by Hartman et al. were tested to characterize the relationship between plasma THC concentration and the change in SDLP. The PBPK-PD model was developed based on a THC clinical trial with inhaled THC administration that reported both plasma THC concentration and SDLP values. The established model was subsequently verified using clinical data from published studies on inhaled THC in healthy adults. The accuracy of the model predictions was assessed by comparing the observed mean SDLP values with those predicted within the 5th to 95th percentile range.
Results
The linear model well describes THC-induced driving impairment within 1 hour post-dose. However, SDLPs after 1 hour in validation groups were under-predicted.
Significance
Our study demonstrated that this preliminary PBPK/PD model accurately predicts THC-induced driving impairment within 1 hour post dose. The model will require further refinement and incorporation of additional clinical data to more accurately characterize THC-induced driving impairment over longer time periods.
Location
University of the Pacific, DeRosa University Center
Start Date
24-4-2026 11:00 AM
End Date
24-4-2026 2:00 PM
Exploring the Impact of Delta-9-Tetrahydrocannabinol (THC) on Driving Performance Using A Physiologically Based Pharmacokinetic/Pharmacodynamic Model
University of the Pacific, DeRosa University Center
Delta-9-tetrahydrocannabinol (THC) is the primary cannabinoid responsible for the psychoactive effects of Cannabis (family Cannabaceae). The increasing use of cannabis for both recreational and therapeutic applications has brought attention to THC. Impairment in driving performance is one of the important psychoactive effects that may lead to motor vehicle accidents. By 2023, THC-positive drivers represented approximately 32% of drivers tested for drugs in fatal crashes. Therefore, it is critical to understand the dose-exposure-response relationship between THC and the degree of driving performance impairment.
