Amlodipine, a calcium channel inhibitor, and cocaine and ethanol's reinforcing effects

The effects of amlodipine (from 0.1 to 3.0 mg/kg) on rats' pressing for rew arding brain stimulation, with and without cocaine administration, were ass essed. None of the doses reliably modified the effects of cocaine. Also, am lodipine was given to two groups of rats taking alcohol: one group that was regularly taking a sweetened alcoholic beverage and the ether taking an un sweetened alcoholic beverage. The only discernible effects of amlodipine on alcohol intake were associated with the highest dose and only with rats ta king the sweetened beverage. The effects of this high dose could easily be attributable to behavioral toxicity elicited by the dose. In contrast, and confirming previous work, isradipine, another calcium channel inhibitor, pr oduced reliable reductions on both cocaine's and alcohol's reinforcing effe cts. Despite the similarity of isradipine and amlodipine, isradipine appare ntly has some unique features with respect to cocaine and alcohol. (C) 1999 Elsevier Science Inc.