Publications by authors named "J I Freijer"

Article Synopsis
  • The study enhances understanding of oxycodone pharmacokinetics (PK) and its effects on µ-opioid receptor binding by integrating data from multiple research sources.
  • A two-step modeling approach was utilized, combining existing studies (model-based meta-analysis) with new clinical trial data to accurately characterize oxycodone's PK and its influence on pupil diameter as a biomarker.
  • Results revealed a two-compartmental PK model for oxycodone, confirmed by new data, showing a longer apparent half-life and supporting the development of a Hill equation for drug effect, verifying the prior model parameters.
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Objective: The main aim of this analysis was to characterize the pharmacokinetics (PK) of tapentadol in pediatric patients from birth to <18 years old who experience acute pain, requiring treatment with an opioid analgesic.

Patients And Methods: Data from four clinical trials and 148 pediatric patients who received a single dose of tapentadol oral or intravenous solution were included. Population PK analysis was performed to determine the contribution of size-related (bodyweight) and function-related (maturation) factors to the changes in oral bioavailability (F), volume of distribution (V), and clearance (CL) with age.

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Objective: The main aim of this analysis was to characterize the pharmacokinetics (PK) of the strong analgesic tapentadol in 2-year-old to <18-year-old patients with acute pain and to inform the optimal dosing strategy for a confirmatory efficacy trial in this patient population.

Methods: The analysis dataset included tapentadol concentrations obtained from 92 pediatric patients receiving a single tapentadol oral solution (OS) dose of 1.0 mg/kg bodyweight in two single-dose PK clinical trials.

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The psychomimetic effects that occur after acute administration of ketamine can constitute a model of psychosis and antipsychotic drug action. However, the optimal dose/concentration has not been established and there is a large variety in outcome measures. In this study, 36 healthy volunteers (21 males and 15 females) received infusions of S(+)-ketamine or placebo to achieve pseudo-steady state concentrations of 180 and 360 ng/mL during two hours.

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