Carvedilol for Psychostimulant Dependence

Inclusion Criteria: * 18-45 years old * Cocaine dependence, as assessed by the substance abuse section of the Structured Clinical Interview for DSM-IV. * At least weekly self-reported cocaine use during a preceding three month period * Urine toxicology screen positive for cocaine or cocaine metabolite * Women of childbearing age must have a negative pregnancy test, agree to adequate contraception to prevent pregnancy during the study, agree to monthly pregnancy testing and not be nursing Exclusion Criteria: * Suicide attempts within the past 12 months or suicidal ideations or psychotic symptoms in the past 6 months as determined by a study physician. * Current opioid, alcohol or sedative physical dependence or amphetamine dependence. * Major cardiovascular disorder that contraindicates study participation (e.g., history of myocardial infarction, stroke, congestive heart failure, cardiac arrhythmia, significant hypertension \[i.e., \>170 SBP or \>110 DBP\] or an unstable medical condition (e.g., untreated bacterial infection) as determined by the study physician. * Asthma or chronic obstructive pulmonary disease. * History of schizophrenia, or bipolar type I disorder. * Use of medications that would be expected to have major interaction with carvedilol (e.g., rifampin, cimetidine, digoxin, diuretics). * Medical contraindication to receiving carvedilol (e.g., diabetes, severe bradycardia, bronchial asthma or other bronchospastic condition, 2nd or 3rd degree AV block, sick sinus rhythm, severe hepatic impairment, documented hypersensitivity to carvedilol). * Patients currently taking selective serotonin re-uptake inhibitors, antipsychotics and antidepressants (e.g., amitriptyline and imipramine). * Liver function tests (i.e., liver enzymes) greater than three times normal levels. * Systolic blood pressure \> 170 mmHg or \< 90 mmHg, diastolic blood pressure \> 110 mmHg or \< 60 mmHg, or heart rate of \> 110 beats/min or \< 55 beats/min. Supine blood pressure of 100/65 mm Hg or lower, a seated blood pressure of 90/60 mm Hg or lower, or an orthostatic change of \>20mm Hg systolic or 10 mm Hg diastolic on standing. * Participants with estimated glomerular filtration rate \< 30 ml/min. * Pregnant or nursing female.