title: The interaction of cocaethylene and cocaine and of cocaethylene and alcohol on schedule-controlled responding in rats.
abstract: BACKGROUND
  Cocaethylene is a unique metabolite of cocaine, produced only in the presence of alcohol. This metabolite is pharmacologically, physiologically and behaviorally active. Further, it has been reported to interact pharmacokinetically with both cocaine and alcohol, an interaction that may mediate, in part, the interaction of cocaine and alcohol. Although cocaethylene has been shown to interact with both cocaine and alcohol, behavioral assessments of these interactions are limited.
  
  
  OBJECTIVE
  To examine directly the behavioral interactions between cocaethylene and cocaine and between cocaethylene and alcohol, the present study assessed the effects produced by these combinations on schedule-controlled responding.
  
  
  METHODS
  Rats were first administered cumulative doses of cocaethylene, cocaine and alcohol to assess their effects alone on responding. Following this, doses of cocaethylene were combined with cumulative doses of cocaine or alcohol. Additionally, doses of cocaine or alcohol were given in combination with cumulative doses of cocaethylene.
  
  
  RESULTS
  When administered alone, cocaethylene, cocaine and alcohol produced dose-related decreases in responding. Further, cocaethylene shifted the dose-response functions for both cocaine and alcohol to the left and down, while cocaine and alcohol shifted the dose-response function for cocaethylene to the left and down. An isobolographic analysis revealed that these interactions were additive in nature.
  
  
  CONCLUSIONS
  The present study suggests behavioral interactions between cocaethylene and cocaine and between cocaethylene and alcohol. The contribution of cocaethylene to the enhanced effects produced by the co-administration of cocaine and alcohol was discussed.
authors.affiliation: Department of Psychology, American University, Washington, DC 20016, USA. bs5482@hotmail.com
authors.forename: B F
authors.initials: BF
authors.lastname: Sobel
authors.forename: A L
authors.initials: AL
authors.lastname: Riley
mesh_terms: D000818:Animals; D003042:Cocaine / Q000031:analogs & derivatives* / Q000494:pharmacology*; D003216:Conditioning, Operant / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D000431:Ethanol / Q000494:pharmacology*; D005260:Female; D051381:Rats; D020318:Rats, Long-Evans
chemical_list: D000431:Ethanol; C066444:cocaethylene; D003042:Cocaine