Conditions: Cocaine Use Disorders
Keywords: substance-related disorders
Allocation: RANDOMIZED | Intervention model: PARALLEL
Enrollment: 79
Healthy volunteers: no

Brief summary:
The purpose of this study is to explore the use of d-cycloserine (DCS) to facilitate extinction of response to cocaine cues in cocaine-dependent individuals, in hopes that it may lead to the development of new treatment options for cocaine dependence.

Detailed description:
Cocaine dependence remains a serious problem in the United States today and in spite of two decades of intense research, efficacious pharmacotherapeutic treatments have not been identified. Cocaine-associated environmental cues can elicit drug craving and exposure to cocaine-related cues is likely to be involved in relapse. Emerging data supports the role of glutamate in extinction learning. D-cycloserine (DCS), a partial glutamate agonist, facilitates extinction of associative learning in animal models of fear-conditioning and clinical studies of exposure treatment for anxiety disorders. A recent study demonstrated DCS acceleration of extinction of cocaine-induced conditioned place preference in rats (Botreau et al., 2006). Exploration of DCS in facilitating extinction of response to drug-related cues in humans is needed. The proposed study will extend these innovative and promising findings from the basic science arena and anxiety disorders field in a proof of concept investigation of DCS facilitation of extinction of response to cocaine-related cues in a human laboratory paradigm. In addition, to examine the neural substrates of extinction learning, a sub-set of individuals that are willing and eligible will undergo fMRI scanning procedures before and after the extinction protocol.

Arms:
arm 1: Participants were assigned to receive placebo for each of 3 cue exposure sessions and at the one-week follow-up session. During cue exposure sessions, participants were asked to handle cocaine cues such as simulated crack, powder, and pipes while listening to an imagery script, and then they watched video footage of cocaine-related activities. arm 2: Participants were assigned to receive 50 mg of d-cycloserine (DCS) for each of 3 cue exposure sessions and a placebo at the one-week follow-up session. During cue exposure sessions, participants were asked to handle cocaine cues such as simulated crack, powder, and pipes while listening to an imagery script, and then they watched video footage of cocaine-related activities. arm 3: Participants were assigned to receive 50 mg of d-cycloserine (DCS) at the first and third cue exposure sessions and a placebo at the second cue exposure and the one-week follow-up session. During cue exposure sessions, participants were asked to handle cocaine cues such as simulated crack, powder, and pipes while listening to an imagery script, and then they watched video footage of cocaine-related activities. arm 4: Participants were assigned to receive 50 mg of d-cycloserine (DCS) for each of 2 cue exposure sessions and a placebo at the one-week follow-up session. During cue exposure sessions, participants were asked to handle cocaine cues such as simulated crack, powder, and pipes while listening to an imagery script, and then they watched video footage of cocaine-related activities. Cue exposure sessions were accompanied by instructions on coping with craving. arm 5: Participants were assigned to placebo for each of 2 cue exposure sessions and a placebo at the one-week follow-up session. During cue exposure sessions, participants were asked to handle cocaine cues such as simulated crack, powder, and pipes while listening to an imagery script, and then they watched video footage of cocaine-related activities. Cue exposure sessions were accompanied by instructions on coping with craving.

Interventions: intervention 1: D-Cycloserine (DCS) intervention 2: Placebo
Intervention descriptions: intervention 1: 50 mg d-cycloserine or placebo taken orally intervention 2: None

Protocol document: