In a double-blind, placebo-controlled 12-week randomized clinical trial, we compared amantadine hydrochloride (300 mg/d; n = 33), desipramine hydrochloride (150 mg/d; n = 30), and placebo (n = 31) in the treatment of cocaine-abusing methadone-maintained patients. Treatment retention and medication compliance were excellent, with more than 75% of the patients completing the full 12-week trial. Although reported cocaine abuse was significantly lower in the medicated groups compared with the placebo group at week 4, this difference became nonsignificant at week 8, and no difference was found in cocaine-free urine samples. Future studies of amantadine and desipramine treatment in these patients should consider alternatives to methadone hydrochloride, such as buprenorphine hydrochloride, and the selection of more homogeneous patient subgroups, such as depressed cocaine abusers.