Olanzapine in cocaine dependence: a double-blind, placebo-controlled trial.

Preclinical and uncontrolled human studies have suggested the possible efficacy of second-generation antipsychotics, particularly olanzapine, in treating cocaine dependence. We conducted a randomized, double-blind, placebo-controlled trial in which 48 cocaine-dependent subjects received olanzapine or identical-appearing placebo for 16 weeks. The primary outcome measure was the proportion of cocaine-negative weekly urine screens during treatment. Secondary measures included scores on a Craving Questionnaire, Addiction Severity Index subscales, and extrapyramidal symptom scales. Olanzapine and placebo did not differ on any outcome measure. Both olanzapine and placebo subjects frequently reported side effects, but no unexpected ones. We conclude that olanzapine appears ineffective for cocaine dependence.