title: Oral and transdermal DL-methylphenidate-ethanol interactions in C57BL/6J mice: potentiation of locomotor activity with oral delivery.
abstract: OBJECTIVE
  Many abusers of dl-methylphenidate co-abuse ethanol. The present animal study examined behavioral effects of oral or transdermal DL-methylphenidate in combination with a high, depressive dose of ethanol to model co-abuse.
  
  
  METHODS
  Locomotor activity of C57BL/6J mice was recorded for 3 h following dosing with either oral DL-methylphenidate (7.5 mg/kg) or transdermal DL-methylphenidate (Daytrana®;1/4 of a 12.5 cm(2) patch; mean dose 7.5 mg/kg), with or without oral ethanol (3 g/kg). Brains were enantiospecifically analyzed for the isomers of methylphenidate and the transesterification metabolite ethylphenidate.
  
  
  RESULTS
  An otherwise depressive dose of ethanol significantly potentiated oral DL-methylphenidate induced increases in total distance traveled for the first 100 min (p<0.05). Transdermal DL-methylphenidate increased total distance traveled after a latency of 80 min, though this effect was not potentiated by concomitant ethanol. Mean 3 h brain D-methylphenidate concentrations were significantly elevated by ethanol in both the oral (65% increase) and transdermal (88% increase) groups. The corresponding L-ethylphenidate concentrations were 10 ng/g and 130 ng/g.
  
  
  CONCLUSIONS
  Stimulant induced motor activity in rodents may correlate with abuse liability. Potentiation of DL-methylphenidate motor effects by concomitant ethanol carries implications regarding increased abuse potential of DL-methylphenidate when combined with ethanol.
authors.affiliation: Department of Pharmaceutical and Biomedical Sciences, Medical University of South Carolina, Charleston, SC, United States. ghb2@musc.edu
authors.forename: Guinevere H
authors.initials: GH
authors.lastname: Bell
authors.forename: William C
authors.initials: WC
authors.lastname: Griffin
authors.forename: Kennerly S
authors.initials: KS
authors.lastname: Patrick
mesh_terms: D000279:Administration, Cutaneous; D000284:Administration, Oral; D000818:Animals; D004347:Drug Interactions; D004951:Esterification; D000431:Ethanol / Q000008:administration & dosage* / Q000009:adverse effects; D008124:Locomotion; D008297:Male; D008774:Methylphenidate / Q000008:administration & dosage* / Q000009:adverse effects; D051379:Mice; D008810:Mice, Inbred C57BL
chemical_list: D008774:Methylphenidate; D000431:Ethanol