The Efficacy of Doxazosin for Cocaine Users

• Self reports of cocaine and other drug use and cravings [ Time Frame: throughout the study ] [ Designated as safety issue: No ]
• The urine drug screen results [ Time Frame: throughout the study ] [ Designated as safety issue: No ]

Doxazosin, an alpha 1-adrenergic receptor, may play an important role in cocaine addiction in humans. This study will evaluate the effectiveness of doxazosin in preventing drug relapse among cocaine dependent participants.

The NE system, especially the alpha 1-adrenergic receptor, may play an important role in cocaine addiction in humans. The results of this study will provide medical safety data on the duration of the induction schedule that will be optimal for attaining our target dose of 8 mg doxazosin daily and will guide future pharmacotherapy trials using Doxazosin or related alpha 1 receptor antagonists for cocaine addiction.

This 17-week double-blind, placebo controlled clinical trial includes a 13 week medication trial (weeks 1-13) and up to 4 week washout period(weeks 14-17). Qualifying subjects will be randomized to receive Doxazosin 8 mg/day, or placebo during the study participation.

Subjects will be receiving 1 mg study medication/placebo capsules at week 1, with 1mg/week induction rate for 8 weeks, according to their randomized assignments, and are maintained on these agents through week 13. At the end of the study (weeks 14-17), participants will undergo discontinuation from active/placebo medication over a 4-week period. Subjects who wish to be transferred to an appropriate treatment program or treatment-research program will be helped with referral during the 4 week period (weeks 14-17).

• Drug: Doxazosin
  The target dose of 8 mg will probably not be attained by some patients over a 8 week induction period (starting at week 1 of the overall 17 week study). We will try to increase the subjects' dose up to a minimum of 4 mg and optimum of 8 mg daily as once daily dosing. The starting dose will be 1 mg once daily at week 1, then 2 mg once daily at week 2, with 1mg/week induction rate for 8 weeks. They will be maintained on 4mg-8mg daily dosing until week 13. The subjects will be undergo the discontinuation from the study medication during weeks 14 -17.
  Other Name: Cardura (Doxazosin Mesylate)
• Drug: Placebo
  Placebo daily dosing
  Other Name: sugarpills ( Capsules)

• Experimental: Doxazosin
  The starting dose will be 1 mg once daily at week 1 of the overall 17 week study, then 2 mg at week 2, with 1mg/week induction rate for 8 weeks. The target dose of 8 mg daily will probably not be attained by some patients over a 8 week induction period. We will try to increase their dose up to a minimum of 4 mg and optimum of 8 mg daily as daily dosing.
  Intervention: Drug: Doxazosin
• Placebo Comparator: placebo
  Intervention: Drug: Placebo

Inclusion Criteria:

• Meets DSM-IV diagnosis criteria for cocaine dependence, as determined by self-reported use of cocaine at least once weekly for at least 1 month prior to study entry; a positive urine test for cocaine; and a score greater than 3 on the Severity of Dependence Scale
• If female, willing to use contraception throughout the study

Exclusion Criteria:

• Meets DSM-IV diagnosis criteria for dependence on any drugs other than cocaine, or tobacco
• Current major psychiatric illness, including schizophrenia, bipolar disorder, or other psychotic disorder
• Current suicidal or homicidal ideation
• Current use of a prescribed psychotropic medication that cannot be discontinued
• History of or current major medical illness, including major heart, kidney, endocrine, or liver disorder; abnormal liver function (SGOT or SGPT levels three times greater than normal); or high blood pressure or low blood pressure
• High risk factor for heart disease, seizure disorders, or any illness for which disulfiram or methadone treatment would be inadvisable
• Currently taking metronidazole or clotrimazole
• Pregnant or breastfeeding