The purpose of this study is to examine the safety of two consecutive days of metyrapone (MRP) in subjects who may use cocaine concurrently.

To evaluate the safety of metyrapone (MRP) for using in an outpatient study in which participants would be given 2 750 mg doses of MRP per week. Secondary study goals are to evaluate the possible efficacy of MRP as a treatment for cocaine dependence and to compare 3 factors hypothesized to induce cocaine craving: cocaine cues, stress, and cocaine itself. This study will utilize a Double Blind, placebo-controlled crossover design with 3 factors: 1) medication 2) relapse trigger and 3) infusion for an 11 day in-patient treatment.

Inclusion Criteria:

Male or Females between 18 and 45 yrs of age; cocaine dependence according to DSM-4; females of child-bearing potential must test non-pregnant and use adequate birth control; be able to provide consent, comply with protocol requirements and try to complete all study treatments.

Exclusion Criteria:

Additional criteria available during screening at the site.