Related Experiment Video
Updated: Aug 9, 2026

Guidelines for Elective Pediatric Fiberoptic Intubation
Published on: January 17, 2011
Nalmefene to prevent epidural narcotic side effects in pediatric patients: a pharmacokinetic and safety study
Insights
Nalmefene demonstrated similar pharmacokinetics in children as in adults, indicating safe administration. However, the 1 microg/kg dose did not effectively prevent narcotic side effects from epidural anesthesia in pediatric patients.
Area of Science:
- Pharmacology
- Pediatric Anesthesiology
Background:
- Epidural anesthesia is commonly used in pediatric surgery.
- Narcotic analgesics administered epidurally can cause side effects like nausea, vomiting, and urinary retention.
- Nalmefene, an opioid antagonist, is used in adults to counteract opioid effects.
Purpose of the Study:
- To evaluate the pharmacokinetics of nalmefene in children.
- To assess the preliminary efficacy of nalmefene in preventing epidural-induced narcotic side effects in pediatric patients undergoing cardiothoracic surgery.
Main Methods:
- A double-blind, placebo-controlled study was conducted with 34 children (aged 2-12 years).
- Patients received either intravenous bolus nalmefene (1 microg/kg) or a placebo.
- Plasma nalmefene concentrations were measured, and pharmacokinetic parameters were analyzed using a limited sampling strategy and Bayesian analysis.
Main Results:
- Nalmefene pharmacokinetic parameters in children were similar to those reported in adults.
- The initial disposition half-life was 0.36+/-0.11 hour, and the terminal elimination half-life was 8.7+/-2.3 hours.
- The 1 microg/kg dose of nalmefene did not significantly prevent or reduce epidural narcotic-induced side effects (pain, nausea, vomiting, urinary retention) compared to placebo.
Conclusions:
- Nalmefene exhibits comparable pharmacokinetics in pediatric and adult populations.
- The drug was safely administered to pediatric patients without causing unmanageable pain.
- The studied dose of nalmefene was not effective in preventing common side effects associated with epidural narcotics in children.
Study Objective:
To determine the pharmacokinetics and preliminary efficacy of nalmefene in children in preventing epidural-induced narcotic side effects.
Design:
Double-blind, placebo-controlled study.
Setting:
University-affiliated children's hospital.
Patients:
Thirty-four children (aged 2-12 yrs) undergoing cardiothoracic surgery with epidural anesthesia.
Interventions:
Patients were randomized to receive intravenous bolus nalmefene 1 microg/kg or placebo.
Measurements And Main Results:
Six blood samples (one before nalmefene administration and five from 13 randomly designated time points) from each patient were assayed to determine plasma nalmefene concentrations. Patients were assessed for pain, nausea, vomiting, and urinary retention for 24 hours after administration. Concentration-time data were analyzed by a limited sampling strategy with adult pharmacokinetic parameters used as Bayesian priors. A two-compartment, first-order model was fitted to the data using ADAPT II. Pharmacokinetic parameter estimates in these patients were similar to values reported in adults. The initial disposition half-life (t(1/2alpha)) was 0.36+/-0.11 hour, the terminal elimination half-life (t(1/2beta)) 8.7+/-2.3 hours, clearance 0.729+/-0.172 L/kg/hr, and steady-state volume of distribution 7.21+/-2.49 L/kg. Ability to prevent epidural narcotic-induced side effects could not be documented at the 1-microg/kg dose. No statistically significant differences were noted between study and placebo groups with regard to pain, nausea, vomiting, or urinary retention.
Conclusion:
Nalmefene has similar pharmacokinetics in children as in adults. It was administered safely to these patients and did not produce unmanageable pain.
Related Concept Videos
Local Anesthetics: Clinical Application as Epidural Anesthesia
Since epidural anesthetics can be infused through an epidural catheter, all types of drugs, including short-acting ones, can be administered. Chloroprocaine and lidocaine are examples of short and long-duration anesthetics, respectively. Bupivacaine...
Opioid Analgesics: Synthetic and Semisynthetic Opioids
Parenteral Anesthetics: Overview
Drug Delivery: Enteral Route
Drugs in...
Pharmacokinetics in Pediatric Patients: Overview and Drug Absorption
Pharmacokinetics in Pediatric Patients: Drug Distribution

