Glutamatergic Modulation to Facilitate Naltrexone Initiation in Opioid Dependence

Opioid dependence is a substantial problem associated with significant morbidity and mortality. Extended-release naltrexone has been found effective at reducing opioid use and maintaining abstinence, but its use has been limited by the difficulties encountered with treatment initiation, which involves detoxification from opioids and oral naltrexone titration. Improving the likelihood of a successful transition to naltrexone is therefore an important public health goal. N-methyl-D-aspartate receptor (NMDA) antagonism has been found to alleviate the signs and symptoms of withdrawal from opioids, as well as to address adaptations associated with chronic opioid use, such as opioid-induced hyperalgesia (increased pain sensitivity). These benefits may persist for at least 72 hours after a single dose. NMDA antagonism may therefore facilitate a rapid transition to naltrexone by reducing discomfort, improving motivation, and ameliorating adaptations associated with drug dependence, such as craving and arousal. The purpose of this trial is to assess the feasibility of NMDA antagonist-assisted naltrexone initiation in opioid dependent individuals. After administration of extended-release naltrexone, participants will be followed for 4 weeks, and transitioned to appropriate care subsequently (oral naltrexone, extended-release naltrexone).