Titre du document / Document title

Epinephrine increases spinal cord concentrations of [³H]-clonidine hydrochloride in rabbits after epidural infusion

Auteur(s) / Author(s)

FU E. S. ⁽¹⁾ ; NAIDU K. A. ⁽²⁾ ; PROCKOP L. D. ⁽²⁾ ;

Affiliation(s) du ou des auteurs / Author(s) Affiliation(s)

⁽¹⁾ Department of Anesthesiology, University of South Florida College of Medicine, Tampa, Florida, ETATS-UNIS
⁽²⁾ Department of Neurology, University of South Florida College of Medicine, Tampa, Florida, ETATS-UNIS

Résumé / Abstract

Epinephrine is often given with epidurally administered drugs to prolong and enhance analgesia, which is partly attributed to α-adrenergic processes. This investigation evaluates the effect of epinephrine on the distribution of epidurally administered [³H]-clonidine hydrochloride (clonidine HCI) in serum and in the central nervous system. After placing a lumbar epidural catheter via a laminectomy, rabbits were randomly assigned to receive 20 μCi of clonidine HCI with epinephrine (1:200,000) (n = 5) or without (control; n = 5) for 90 min. During the administration, which included bolus and slow infusion, blood samples were collected at 15-min intervals. At the end of the administration, rabbits were perfused with normal saline, leading to exsanguination. Brain and spinal cord tissues were excised for radiometric analysis. In both groups, the concentration of clonidine HCl was greatest in the lumbar cord. Epinephrine further enhanced accumulation of clonidine HCI into the lumbar cord but did not alter the concentration of clonidine HCI in serum, brain, cervical cord, and thoracic cord. We conclude that lumbar administration of epidural clonidine HCl leads to increased concentrations in the lumbar cord, which is further enhanced by epinephrine. The increased spinal cord accumulation of clonidine maybe another mechanism by which epinephrine improves epidural analgesia.

Revue / Journal Title

Anesthesia and analgesia   ISSN 0003-2999   CODEN AACRAT 

Source / Source

Congrès
1996 Annual meeting of the American Society of Anesthesiologists, New Orleans, LA , ETATS-UNIS
1997, vol. 85, n^o2, pp. 324-327 (18 ref.)

Langue / Language

Anglais

Editeur / Publisher

Lippincott, Hagerstown, MD, ETATS-UNIS  (1957) (Revue)

Mots-clés anglais / English Keywords

Clonidine ; Agonist ; α2-Adrenergic receptor ; Analgesic ; Extradural administration ; Drug combination ; Epinephrine ; Drug interaction ; Pharmacokinetics ; Spinal cord ; Rabbit ; Animal ; Central nervous system ; Lagomorpha ; Mammalia ; Vertebrata ;

Mots-clés français / French Keywords

Clonidine ; Agoniste ; Récepteur α2-adrénergique ; Analgésique ; Voie extradurale ; Association médicamenteuse ; Adrénaline ; Interaction médicamenteuse ; Pharmacocinétique ; Moelle épinière ; Lapin ; Animal ; Système nerveux central ; Imidazoline dérivé ; Lagomorpha ; Mammalia ; Vertebrata ;

Mots-clés espagnols / Spanish Keywords

Clonidina ; Agonista ; Receptor α2-adrenérgico ; Analgésico ; Vía extradural ; Asociación medicamentosa ; Adrenalina ; Interacción medicamentosa ; Farmacocinética ; Médula espinal ; Conejo ; Animal ; Sistema nervioso central ; Lagomorpha ; Mammalia ; Vertebrata ;

Localisation / Location

INIST-CNRS, Cote INIST : 3213, 35400006787098.0140