Kappa-opioid attenuation of cocaine-produced drug-seeking

Abstract

High rates of recidivism are a major threat to the effective long-term treatment of cocaine dependence and addiction (O'Brien, 1997). Currently, there is no effective medication for cocaine addiction (O'Brien and Gardner, 2005), and relapse prevention is still the most common way to maintain abstinence. Nevertheless, as many as 80% of treated cocaine abusers relapse, and research into effective pharmacological treatments should continue to be undertaken. In the present study, the drug priming reinstatement model of relapse (within session reinstatement procedure) was used to evaluate the capacity of three different Κ-opioid receptor agonists (U69593, U-50,488, and spiradoline - U-62,066), to attenuate relapse to cocaine seeking in rats. K-opioid receptor agonists were administered systemically. Cocaine priming injections dose-dependently reinstated extinguished cocaine self-administration. Systemic pre-treatment with all three kappa-opioid receptor agonists attenuated this effect. However, only the effect of a priming injection of 20 mg/kg cocaine was significantly decreased by all three kappa-opioid receptor agonists. The present research supports the continued investigation that kappa-opioid agonists may represent a pharmacological treatment to aid relapse prevention.