Imipramine treatment of cocaine abuse: possible boundaries of efficacy.

A 12-week placebo-controlled, randomized clinical trial was undertaken to evaluate imipramine as a treatment for cocaine abuse, and to examine whether its effect may be limited to subgroups defined by route of use or by diagnosis of depression. One-hundred thirteen patients were randomized, stratified by route of use and depression. All patients received weekly individual counseling. Compared to placebo the imipramine group showed greater reductions in cocaine craving, cocaine euphoria, and depression, but the effect of imipramine on cocaine use was less clear. A favorable response, defined as at least 3 consecutive, urine-confirmed, cocaine-free weeks was achieved by 19% (11/59) of patients on imipramine compared to 7% (4/54) on placebo (P < 0.09). The imipramine effect was greater among nasal users--33% (9/27) response on imipramine vs. 5% (1/22) on placebo (P < 0.02). Response was also more frequent, but not significantly so, among depressed users on imipramine (26%, 10/38) than on placebo (13%, 4/31) (P < 0.19). Response rates were low in intravenous and freebase users and those without depression. Considered together with the literature on desipramine, these data suggest tricyclic antidepressants are not promising as a mainstay of treatment for unselected cocaine abusers. However, tricyclics may be useful for selected cocaine abusers with comorbid depression or intranasal use, or in conjunction with a more potent psychosocial intervention.