Titre du document / Document title

Evaluation of the intravenous reinforcing effects of clonidine in baboons

Auteur(s) / Author(s)

WEERTS E. M. ⁽¹⁾ ; GRIFFITHS R. R. ⁽²⁾ ;

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

⁽¹⁾ Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, 5510 Nathan Shock Dr./ Suite 3000, Baltimore, MD 21224, ETATS-UNIS
⁽²⁾ Department of Psychiatry and Behavioral Sciences, Department of Neuroscience, Johns Hopkins University School of Medicine, 5510 Nathan Shock Dr./ Suite 3000, Baltimore, MD 21224, ETATS-UNIS

Résumé / Abstract

Clonidine HCI is an antihypertensive that is also sometimes used to alleviate symptoms of withdrawal during narcotics detoxification. Recently, there have been reports abuse of clonidine by methadone patients and opioid abusers. The present study evaluated the intravenous self-administration of clonidine in four baboons. Self-injections were available 24 h/day under a fixed-ratio (FR 120 or 160) schedule of injection with a 3-h timeout after each injection. Doses of clonidine (0.0001-0.056 mg/kg per injection) or its vehicle (saline) were substituted for cocaine (0.32 mg/kg) for at least 15 days. Food pellets were available continuously under a concurrent FR 30 schedule of pellet delivery. Clonidine maintained self-injection greater than its saline vehicle in all four baboons. Although self-injection of clonidine increased as a function of dose within each baboon, there were differences between baboons in the range of doses of clonidine that maintained self-injection. Doses of 0.032 or 0.056 mg/kg maintained peak mean levels of clonidine self-injection which ranged from low (3.2 injections/day) to high ( > 6 injections/day) across baboons. Levels of self-injection were similar to vehicle at 0.01 mg/kg clonidine in two of four baboons. However, in the other two baboons, very low doses of clonidine (0.0001-0.001 mg/kg) maintained low to moderate levels of self-injection. Acute administration of clonidine produced signs of sedation including lip droop, drooling and sitting with eyes closed. At high doses, some toxicity was apparent: Baboons were pale and not responsive. Food intake was generally increased in a dose dependent manner. The present study indicates that clonidine functions as a positive reinforcer.

Revue / Journal Title

Drug and alcohol dependence   ISSN 0376-8716   CODEN DADEDV 

Source / Source

1999, vol. 53, n^o3, pp. 207-214 (33 ref.)

Langue / Language

Anglais

Editeur / Publisher

Elsevier, Shannon, IRLANDE  (1975) (Revue)

Mots-clés anglais / English Keywords

Clonidine ; Intravenous administration ; Risk factor ; Dependence ; Experimental study ; Self administration ; Instrumental conditioning ; Acquisition process ; Positive reinforcement ; Papio anubis ; Monkey ; Animal ; Addictive potential ; Simioidea ; Primates ; Mammalia ; Vertebrata ; α2-Adrenergic receptor ; Agonist ;

Mots-clés français / French Keywords

Clonidine ; Voie intraveineuse ; Facteur risque ; Dépendance ; Etude expérimentale ; Autoadministration ; Conditionnement instrumental ; Processus acquisition ; Renforcement positif ; Papio anubis ; Singe ; Animal ; Imidazoline dérivé ; Potentiel addictif ; Simioidea ; Primates ; Mammalia ; Vertebrata ; Récepteur α2-adrénergique ; Agoniste ;

Mots-clés espagnols / Spanish Keywords

Clonidina ; Vía intravenosa ; Factor riesgo ; Dependencia ; Estudio experimental ; Autoadministración ; Condicionamiento instrumental ; Proceso adquisición ; Reforzamiento positivo ; Papio anubis ; Mono ; Animal ; Simioidea ; Primates ; Mammalia ; Vertebrata ; Receptor α2-adrenérgico ; Agonista ;

Localisation / Location

INIST-CNRS, Cote INIST : 16471, 35400007425169.0030