Effect of cocaine use on buprenorphine pharmacokinetics in humans.

The effect of chronic cocaine use on buprenorphine pharmacokinetics was investigated to identify drug interactions and potential toxicities. In a retrospective analysis, pharmacokinetics were compared for 16 studies completed on subjects who were regular cocaine users and 74 studies on subjects who used cocaine only occasionally or not at all. All participants were stably maintained on buprenorphine/naloxone 16/4 mg daily. Participants who used cocaine regularly had lower buprenorphine exposure (AUC 34% lower; C(max) 27% lower and C(24) 37% lower; p <or= .001 for all comparisons). Regular cocaine users were younger (p = .0007), and used more heroin (p = .004) and cocaine (p < .0001). Regular cocaine use may result in lower buprenorphine plasma concentrations with potential for adverse clinical outcomes.