Role of the Orexin Receptor System in Stress, Sleep and Cocaine Use

Role of the Orexin Receptor System in Stress, Sleep and Cocaine Use

The purpose of this study is to determine the effectiveness of a medication called suvorexant in reducing anxiety, improving sleep, and reducing cocaine cravings or cocaine use.

Preclinical research has established important functions for the orexin system in mediating arousal/sleep, stress, and cue-induced reinstatement of drug taking (e.g., relapse). The role of stress/anxiety and drug cue reactivity in human drug relapse is well established, but to date, the role of the orexin system in modulating these phenomena has not been examined in humans with substance use disorders (e.g., cocaine). The goal of the present first-in-human study will be to examine the effects of an orexin antagonist (suvorexant) on interactions among stress/anxiety, sleep, and drug-cue reactivity. The study will utilize a battery of highly sensitive, drug-specific, laboratory measures of drug cue reactivity (a relapse risk model), and well-established metrics of stress/anxiety and sleep. The hypothesis is that antagonism of the orexin system will attenuate the link between (1) stress/anxiety and drug cue reactivity, and (2) sleep and drug cue reactivity. These results will elucidate a unique biochemical mechanism for understanding relapse, and provide a potential medication target for relapse prevention.

Inclusion Criteria:

• meet current DSM-5 criteria for cocaine use disorder (CUD) of at least moderate severity (≥4 symptoms)

Exclusion Criteria:

• current DSM-IV diagnosis of any psychoactive substance dependence other than cocaine, marijuana, or nicotine
• have a DSM-IV axis I psychiatric disorder or neurological disease or disorder requiring ongoing treatment and/or making study participation unsafe
• significant current suicidal or homicidal ideation
• medical conditions contraindicating administration of suvorexant (e.g., severe pulmonary disease, severe cardiovascular disease or clinically abnormal EEG, severe liver or kidney disease, seizure disorder, or sleep disorder - particularly narcolepsy)
• taking medications known to have significant drug interactions with the study medication(s) (e.g., MAO inhibitors, anticonvulsants, haloperidol, phenothiazines, anesthetics, and all sedatives)
• currently or recently (last 3 months) treated for substance use [other than cocaine or nicotine] or another psychiatric condition
• conditions of probation or parole requiring reports of drug use to officers of the court; (8) impending incarceration
• pregnant or nursing for female patients
• inability to read, write, or speak English [required for lab tasks and psychometric scales]
• unwillingness to sign a written informed consent form
• subjects with alcohol use disorders or are drinking > 7 alcoholic drinks per week. All subjects who are excluded will be given referral information to other local treatment programs.