Conditions: Cocaine Dependence
Allocation: RANDOMIZED | Intervention model: CROSSOVER
Enrollment: 8
Healthy volunteers: no

Brief summary:
Cocaine dependence involves problematic neuroadaptations, such as heightened reactivity to cocaine cues, that may be responsive to pharmacological modulation of glutamatergic circuits. Despite promising preclinical findings with n-methyl-d-aspartate receptor (NMDAr) modulators, studies with human subjects have been unsuccessful to date. The purpose of this investigation is to examine the effects of the NMDAr antagonist ketamine, recently found to have potent therapeutic effects in humans, on cue-induced craving and impaired motivation for quitting cocaine in cocaine dependent participants, 24-hours post-infusion.

Detailed description:
In this study, volunteers will undergo a 9 day inpatient trial during which they will receive three counter-balanced infusions (two doses of ketamine and a dose of lorazepam) on three separate days in a within-subject, double-blind, controlled design. Of the various glutamate antagonists available for human use, ketamine will be utilized because its safety profile, pharmacokinetics, and range of tolerable sub-anesthetic dosings have been very well studied. Also, ketamine has shown promise in managing opiate and alcohol use disorders in certain studies, and may therefore be the most likely glutamate antagonist to dampen cue reactivity and increase motivation in cocaine users. If ketamine significantly improves these deficits, this would suggest that the drug should be investigated further for potential utility as a treatment for cocaine dependence.

Arms:
arm 1: Ketamine 0.41 mg/kg infused over 52 min (K1) arm 2: Ketamine 0.71 mg/kg infused over 52 min (K2) arm 3: Lorazepam 2 mg infused over 52 minutes (LZP)

Interventions: intervention 1: Ketamine 0.41 mg/kg intervention 2: Ketamine 0.71 mg/kg intervention 3: Lorazepam 2 mg
Intervention descriptions: intervention 1: 52 minute iv infusion of ketamine 0.41 mg/kg intervention 2: 52 minute iv infusion of ketamine 0.71 mg/kg. This dose follows K1 in all 3 orderings. intervention 3: 52 minute infusion of lorazepam 2 mg. This serves as an active control.

Protocol document: