Pharmacogenetic Trial of Doxazosin for Treatment of Cocaine Abuse
Condition: Cocaine Dependence
MeSH terms: Cocaine-Related Disorders
Study type: Interventional
Phase: Phase 2

Summary: 
      Cocaine use disorders affect approximately 1.5 million Americans annually. Currently, there
      are no US Food and Drug Administration approved medications for treatment of cocaine
      dependence; however, both animal and human studies suggest that medications affecting the
      noradrenergic system can reduce cocaine craving and use. The investigators will study the
      effect of doxazosin, an alpha-1 adrenergic antagonist, in reducing cocaine use and anxiety
      symptoms among cocaine-dependent individuals. In addition, the investigators will identify
      genetic subpopulations of participants who preferentially respond to the medication.
    

Detailed description: 
      The noradrenergic system, especially the alpha 1-adrenergic receptor, may play an important
      role in cocaine addiction in humans. Doxazosin is a long-acting and selective alpha
      1-adrenergic receptor blocker, which inhibits the binding of norepinephrine to alpha
      receptors in the autonomic nervous system. This study will evaluate the efficacy of doxazosin
      in reducing cocaine-using behavior in treatment seeking cocaine-dependent individuals, and
      will guide future pharmacotherapy trials using Doxazosin or related alpha 1 receptor
      antagonists for treatment of cocaine addiction.

      This 12-week double-blind, placebo controlled clinical trial will provide treatment for
      cocaine-dependent patients and includes a 8-week maintenance medication trial (weeks 3-10).
      At the end of this period, subjects will have a 2-week study medication taper (weeks 11-12).
      Qualifying subjects will be randomized to receive Doxazosin up to 8 mg/day or placebo.

      At the beginning of week 1, participants will receive Doxazosin, or placebo according to
      their randomized assignments, and are maintained on these agents through week 12. At the end
      of the study (weeks 11-12), participants will undergo discontinuation from active/inactive
      medication over a 2-week period. Subjects who wish to be transferred to an appropriate
      treatment program or research program will be referred to upon request, during the study
      weeks 11-12.
    

Intervention name(s): Doxazosin; Placebo
Intervention type(s): Drug; Drug
Intervention description(s): Doxazosin is initiated at 2 mg/wk, and titrated up to a maximum of 8 mg/day over approximately 4 weeks. Participants will be maintained on 8mg daily dosing until week 13. The subjects will undergo the discontinuation from the study medication during weeks 14 -15.; Matched placebo daily dosing
Other intervention name(s): Cardura (Doxazosin Mesylate); Sugar pills (capsule)
Intervention MeSH terms: Doxazosin
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary purpose: Treatment
Keywords: Cocaine-Related Disorders; Cocaine; Doxazosin; Cardiovascular Agents; Antihypertensive Agents; Adrenergic alpha-1 Receptor Antagonists; Adrenergic alpha-Antagonists; Adrenergic Antagonists; Molecular Mechanisms of Pharmacological Action; Neurotransmitter Agents; Therapeutic Uses; Pharmacologic Actions; Substance-Related Disorders