Effects of labetalol on cocaine pharmacokinetics in neonatal piglets

F. Scalzo, S. Primozic, L. J. Burge, T. M. Badger, M. H. Creer, C. Nehus, R. Karba

Research output: Contribution to journalArticlepeer-review

3 Scopus citations

Abstract

Developmental exposure to cocaine can produce adverse neurobehavioral and cardiovascular effects. Few animal models of human neonatal exposure have been established. A pharmacokinetic study was therefore conducted to characterize the disposition of cocaine and a major metabolite benzoylecgonine (BE) using piglets as an animal model. Eight piglets (postnatal days 8-9) were instrumented with a jugular cannula for drug administration and blood sampling. One group of subjects (controls) received 6.0 mg/kg of cocaine-HCl (i.v.) and blood samples were drawn over 0-24 h. In another group (labetalol), 0.25 mg/kg labetalol-HCl was coadministered 15 min following cocaine dosing. Plasma levels of cocaine and BE were determined using GC-MS methods. Pharmacokinetics were evaluated by using a model-independent approach and compartmental modeling. For controls model-independent results were as follows: AUC = 148.9 ± 9.0 mg/l x min, systemic clearance = 0.041 ± 0.003 liters/min/kg, volume of distribution = 1.543 ± 0.470 liters/kg, and t( 1/2 β) = 29.4 ± 6.8 min. Cocaine followed two-compartment model kinetics with distribution and elimination half-lives of 0.3 ± 0.1 and 58.0 ± 18.0 min, respectively. Labetalol significantly decreased systemic clearance to 0.029 ± 0.004 liters/min/kg. BE kinetics revealed a elimination half-life of 230.0 ± 83.2 min. The results demonstrate a rapid distribution and metabolism of cocaine to BE followed by a prolonged elimination phase which is extended by labetalol treatment.

Original languageEnglish (US)
Pages (from-to)54-63
Number of pages10
JournalDevelopmental Pharmacology and Therapeutics
Volume20
Issue number1-2
DOIs
StatePublished - 1993

All Science Journal Classification (ASJC) codes

  • Pharmacology, Toxicology and Pharmaceutics(all)
  • Pharmacology (medical)

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