Chronic modafinil effects on drug-seeking following methamphetamine self-administration in rats

Acute administration of the cognitive enhancing drug, modafinil (Provigil®), reduces methamphetamine (Meth) seeking following withdrawal from daily self-administration. However, the more clinically relevant effects of modafinil on Meth-seeking after chronic treatment have not been explored. Here, we determined the impact of modafinil on Meth-seeking after chronic daily treatment during extinction or abstinence following Meth self-administration. Rats self-administered intravenous Meth during daily 2-h sessions for 14 d, followed by extinction sessions or abstinence. During this period, rats received daily injections of vehicle, 30, or 100 mg/kg modafinil and were then tested for Meth-seeking via cue, Meth-primed, and context-induced reinstatement at early and late withdrawal time-points. We found that chronic modafinil attenuated relapse to a Meth-paired context, decreased conditioned cue-induced and Meth-primed reinstatement, and resulted in enduring reductions in Meth-seeking even after discontinuation of treatment. Additionally, we determined that only a very high dose of modafinil (300 mg/kg) during maintenance of self-administration had an impact on Meth intake. These results validate and extend clinical and preclinical findings that modafinil may be a viable treatment option for Meth addiction.