A double blind, placebo-controlled study of the effects of post-retrieval propranolol on reconsolidation of memory for craving and cue reactivity in cocaine dependent humans

This study examined the effects of propranolol vs. placebo, administered immediately after a retrieval session of cocaine cue exposure (CCE), on craving and physiological responses occurring 24 h later during a subsequent test session of CCE. It was hypothesized that compared to placebo-treated cocaine-dependent (CD) individuals, propranolol-treated CD individuals would evidence attenuated craving and physiological reactivity during the test session. Secondarily, it was expected that group differences identified in the test session would be evident at a 1-week follow-up CCE session. Exploratory analyses of treatment effects on cocaine use were also performed at follow-up. CD participants received either 40 mg propranolol or placebo immediately following a retrieval CCE session. The next day, participants received a test session of CCE that was identical to the retrieval session except no medication was administered. Participants underwent a follow-up CCE session 1 week later. Craving and other reactivity measures were obtained at multiple time points during the CCE sessions. Propranolol- vs. placebo-treated participants evidenced significantly greater attenuation of craving and cardiovascular reactivity during the test session. Analysis of the follow-up CCE session data did not reveal any group differences. Although there was no evidence of treatment effects on cocaine use during follow-up, this study was insufficiently powered to rigorously evaluate differential cocaine use. This double-blind, placebo-controlled laboratory study provides the first evidence that propranolol administration following CCE may modulate memories for learning processes that subserve cocaine craving/cue reactivity in CD humans. Alternative interpretations of the findings were considered, and implications of the results for treatment were noted.