title: Buprenorphine-cocaine interactions in mice: effect on locomotor activity and hole-dipping behaviour.
abstract: The effect of cocaine and the mixed mu-opioid partial agonist/kappa-antagonist buprenorphine on locomotor activity and hole-dipping behaviour was investigated in mice. The drugs were given alone and in combination. Cocaine (7.5, 15, 30 mg kg-1, i.p.) significantly increased locomotion in a dose-related manner in the hour following injection. The two highest doses also increased hole-dipping although this response was not consistently seen. Buprenorphine (0.5, 5 mg kg-1, i.p.) produced an increase in locomotion which occurred 30-60 min after injection but did not alter hole-dipping behaviour. A lower dose (0.05 mg kg-1) had no effect on either parameter. The locomotion induced by cocaine (15 mg kg-1, i.p.) was not modified by buprenorphine (0.05, 0.5, 1, 5 mg kg-1, i.p.; 5 min pretreatment). However, hole-dipping was almost completely abolished in animals given combinations of cocaine and buprenorphine (0.05-5 mg kg-1, i.p.), although neither drug decreased hole-dipping when given alone. This observation, which was not simply due to the emergence of stereotyped behaviour, suggests an interaction between buprenorphine and cocaine.
authors.affiliation: Reckitt & Colman Psychopharmacology Unit, Department of Pharmacology, School of Medical Sciences, Bristol, UK.
authors.forename: H C
authors.initials: HC
authors.lastname: Jackson
authors.forename: I J
authors.initials: IJ
authors.lastname: Griffin
authors.forename: D J
authors.initials: DJ
authors.lastname: Nutt
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects*; D002047:Buprenorphine / Q000008:administration & dosage / Q000494:pharmacology*; D003042:Cocaine / Q000008:administration & dosage / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D008297:Male; D051379:Mice; D009043:Motor Activity / Q000187:drug effects*
chemical_list: D002047:Buprenorphine; D003042:Cocaine