evidence: As might be expected, an acute injection of buprenorphine given with an acute injection of cocaine produced an increase in DA in the NAc that was higher (approximately 260% of baseline) than that produced by that particular dose of either drug alone. This synergism was also reflected in the reinforcing effects of these drugs when they were administered together during the conditioning of a place preference (Brown et al, 1991). It is not clear how these results from studies using acute injections of buprenorphine can be related to those using chronic treatment with buprenorphine in human opioid addicts and in monkeys trained to self-administer opioids and cocaine. Interestingly, however, there is one report that twice daily injections of buprenorphine, which might be considered to be chronic treatment, attenuated the development of a cocaine conditioned place preference (CPP) (Kosten et al, 1991). [...] Brown EE, Finlay JM, Wong JT, Damsma G, Fibiger HC (1991). Behavioral and neurochemical interactions between cocaine and buprenorphine: implications for the pharmacotherapy of cocaine abuse. J Pharmacol Exp Ther256: 119–126. [...] Kimmel HL, Tallarida RJ, Holtzman SG (1997). Synergism between buprenorphine and cocaine on the rotational behavior of the nigrally-lesioned rat. Psychopharmacology133: 372–377.