Effects of N-acetylcysteine on Brain Chemistry and Behavior in Cocaine Abusers (NAC)

N-acetylcysteine (NAC) is a medication that the Food and Drug Administration (FDA) has approved for several medical uses, such as dissolving mucus in patients with breathing problems, treating overdose from acetaminophen (Tylenol), and protecting the kidneys from toxic substances. Some recent studies suggest that NAC could be useful in the treatment of other disorders including addictions. One purpose of this study is to determine whether NAC alters the level of brain glutamate (a chemical that excites brain cells). The other main purpose is to determine whether NAC affects how much cocaine people use.