Related Experiment Videos
Pharmacokinetics of rocuronium in children aged 4-11 years
1Department of Anesthesiology, Baylor College of Medicine, Texas Children's Hospital, Houston, USA.
Insights
Rocuronium pharmacokinetics in children aged 4-11 years show weight-normalized clearance changes with age. This suggests younger children may need adjusted rocuronium dosing for consistent neuromuscular blockade.
Area of Science:
- Pharmacology
- Pediatric Anesthesia
- Drug Metabolism
Background:
- Rocuronium is a rapid-onset, intermediate-duration nondepolarizing muscle relaxant.
- Pharmacokinetic data for rocuronium are established in adults and the elderly, but lacking in pediatric populations.
- This study addresses the pharmacokinetic profile of rocuronium in children aged 4-11 years.
Purpose of the Study:
- To determine the pharmacokinetics of rocuronium in children aged 4-11 years.
- To investigate the influence of age and weight on rocuronium's pharmacokinetic parameters in this pediatric group.
Main Methods:
- Rocuronium (600 micrograms/kg) was administered to 20 children (4-11 years) under nitrous oxide and <1% halothane anesthesia.
- Plasma samples were collected over 4 hours to measure rocuronium concentrations.
- Pharmacokinetic analysis was performed using sparse-sampling population approaches, including mixed-effects modeling and naive pooled data analysis.
Main Results:
- Weight-normalized plasma clearance of rocuronium demonstrated a significant variation with weight in children (P < 0.01).
- Weight-normalized distributional clearance, central compartment volume, and volume of distribution at steady-state did not vary significantly with weight, height, or age.
- Mixed-effects modeling and naive pooled data analysis yielded similar findings regarding these pharmacokinetic parameters.
Conclusions:
- Maturational changes were identified in the weight-normalized clearance of rocuronium in children.
- No significant maturational changes were observed in weight-normalized distributional clearance or volume of distribution.
- These findings suggest that younger children may require different rocuronium dosing strategies (repeated or continuous administration) for optimal neuromuscular effects and recovery compared to older children.
Background:
Rocuronium is a new nondepolarizing muscle relaxant with a rapid onset and intermediate duration of action. Although the pharmacokinetics of rocuronium have been determined in adults and the elderly, similar data are lacking in children. Accordingly, rocuronium's pharmacokinetics were determined in children aged 4-11 yr.
Methods:
Rocuronium (600 micrograms/kg) was administered to 20 children aged 4-11 yr anesthetized with nitrous oxide and < or = 1% halothane, and four plasma samples were obtained over 4 h to determine rocuronium concentrations. The pharmacokinetics of rocuronium were determined using two sparse-sampling population approaches, mixed-effects modeling, and naive pooled data analysis.
Results:
With mixed-effects modeling, weight-normalized plasma clearance varied with weight (P < 0.01), being 79.4 ml.min-1 + 3.13 ml.kg-1.min-1. Neither weight-normalized distributional clearance (2.67 ml.kg-1.min-1), weight-normalized central compartment volume (106 ml/kg), nor weight-normalized volume of distribution at steady-state (224 ml/kg) varied with weight, height, or age. Similar results were obtained with the naive pooled data approach.
Conclusions:
Maturational changes were observed in rocuronium's weight-normalized clearance but not in its weight-normalized distributional clearance or volume of distribution. Assuming that the duration of rocuronium's neuromuscular effects is influenced by its pharmacokinetics, repeated administration or continuous infusion of rocuronium should result in larger dose requirements and more rapid recovery in younger, compared to older, children.