title: Effects of 7-day continuous D-amphetamine, methylphenidate, and cocaine treatment on choice between methamphetamine and food in male rhesus monkeys.
abstract: BACKGROUND
  Methamphetamine addiction is a significant public health problem for which no Food and Drug Administration-approved pharmacotherapies exist. Preclinical drug vs. food choice procedures have been predictive of clinical medication efficacy in the treatment of opioid and cocaine addiction. Whether preclinical choice procedures are predictive of candidate medication effects for other abused drugs, such as methamphetamine, remains unclear. The present study aim was to determine continuous 7-day treatment effects with the monoamine releaser d-amphetamine and the monoamine uptake inhibitor methylphenidate on methamphetamine vs. food choice. In addition, 7-day cocaine treatment effects were also examined.
  
  
  METHODS
  Behavior was maintained under a concurrent schedule of food delivery (1-g pellets, fixed-ratio 100 schedule) and methamphetamine injections (0-0.32mg/kg/injection, fixed-ratio 10 schedule) in male rhesus monkeys (n=4). Methamphetamine choice dose-effect functions were determined daily before and during 7-day periods of continuous intravenous treatment with d-amphetamine (0.01-0.1mg/kg/h), methylphenidate (0.032-0.32mg/kg/h), or cocaine (0.1-0.32mg/kg/h).
  
  
  RESULTS
  During saline treatment, increasing methamphetamine doses resulted in a corresponding increase in methamphetamine vs. food choice. Continuous 7-day treatments with d-amphetamine, methylphenidate or cocaine did not significantly attenuate methamphetamine vs. food choice up to doses that decreased rates of operant responding. However, 0.1mg/kg/h d-amphetamine did eliminate methamphetamine choice in two monkeys.
  
  
  CONCLUSIONS
  The present subchronic treatment results support the utility of preclinical methamphetamine choice to evaluate candidate medications for methamphetamine addiction. Furthermore, these results confirm and extend previous results demonstrating differential pharmacological mechanisms between cocaine choice and methamphetamine choice.
authors.affiliation: Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, VA, USA.
authors.forename: Kathryn L
authors.initials: KL
authors.lastname: Schwienteck
authors.affiliation: Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, VA, USA; Institute for Drug and Alcohol Studies, Virginia Commonwealth University, USA. Electronic address: mbanks7@vcu.edu.
authors.forename: Matthew L
authors.initials: ML
authors.lastname: Banks
mesh_terms: D000818:Animals; D002755:Choice Behavior / Q000187:drug effects*; D003042:Cocaine / Q000008:administration & dosage / Q000494:pharmacology*; D003913:Dextroamphetamine / Q000008:administration & dosage / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D005502:Food; D008253:Macaca mulatta; D008297:Male; D008694:Methamphetamine / Q000494:pharmacology*; D008774:Methylphenidate / Q000008:administration & dosage / Q000494:pharmacology*; D012646:Self Administration
chemical_list: D008774:Methylphenidate; D008694:Methamphetamine; D003042:Cocaine; D003913:Dextroamphetamine
keywords: Amphetamine; Choice; Cocaine; Methamphetamine; Methylphenidate