Sensitization to the locomotor activating effects of cocaine following cocaethylene-preexposure

The present study assessed the ability of cocaethylene to induce sensitization to the behavioral activating effects of cocaine in the male Sprague-Dawley rat. Preexposure to cocaethylene (15 or 25 mg/kg) significantly enhanced the locomotor activating effects of a subsequent cocaine (15 mg/kg) challenge injection. In addition, acute intraperitoneal administration at several doses (10, 15, or 25 mg/kg) confirmed previous reports of increased bioavailability of cocaine in brain and plasma relative to cocaethylene. These data are discussed in terms of previous work in which a significant augmentation of cocaine-induced locomotor activity was not observed following cocaethylene preexposure.