The Efficacy of Doxazosin for Cocaine Users

Phase 1

Completed

Brief Summary: 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.

Detailed Description: 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.

Medication induction will occur at a rate of 2mg/week until 8mg/day target dose is achieved as follows:

1. Dox-Fast Group: Defined as participants reaching the target dose after a 4-week titration period. Participants will be stabilized on doxazosin or placebo over weeks 4-13 (for Dox-Fast group)

2. Dox-Slow Group: Defined as participants reaching the target dose after an 8-week titration period. Participants will be stabilized on doxazosin or placebo over weeks 8-13 (for Dox-Slow group)

Both groups will be tapered off doxazosin or placebo over study weeks 14-17.

Recruitment & Eligibility

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

Arm && Interventions

Group	Intervention	Description
placebo	Placebo	A sugar pill to mimic the experiment drug, doxazosin, will be administered in the same manner as the experimental drug through the study duration.
Doxazosin	Doxazosin	Medication induction occurred at a rate of 2mg/week until 8mg/day target dose was achieved as follows: 1. Dox-Fast Group: Defined as participants reaching the target dose after a 4-week titration period. Participants were stabilized on doxazosin or placebo over weeks 4-13 (for Dox-Fast group) 2. Dox-Slow Group: Defined as participants reaching the target dose after an 8-week titration period. Participants were stabilized on doxazosin or placebo over weeks 8-13 (for Dox-Slow group) Both groups were tapered off doxazosin or placebo over study weeks 14-17.

Primary Outcome Measures

Name	Time	Method
Cocaine Negative Urines	throughout the study - up to 17 weeks	cocaine urine toxicology samples were obtained thrice weekly and tested for the presence of the cocaine metabolite, benzoylecgonine

Secondary Outcome Measures

Name	Time	Method
# of Participants That Completed the Study	throughout the study - up to 17 weeks	Retention
Adverse Events	throughout study - upto 17 weeks
Weeks of Abstinence	throughout the study - up to 17 weeks	Percentage of participants achieving 2 or more consecutive weeks of abstinence