The purpose of this study is to conduct a drug interaction study with NS2359 and cocaine in cocaine experienced volunteers.

This is a single-center, double-blind, placebo-controlled, randomized, single dose, fixed order, dose escalating inpatient design that will study oral NS2359 in cocaine experienced volunteers.

Inclusion Criteria:

Male or Female, 18-45 yrs of age; females of child-bearing potential using appropriate method of birth control; be able to understand the procedure and agrees to participate via informed consent; must be cocaine dependent according to DSM-4 criteria; must be capable of providing written consent; must be able to comply with protocol requirement, CPU rules and regulations; must not be currently seeking treatment for cocaine abuse.

Exclusion Criteria:

Incapable of understanding the informed consent process; Additional criteria available during screening at the site.