A NEW clinical study by Romach et al1 reports that the D1 selective antagonist ecopipam (SCH 39166) blocks the subjective effects of intravenous cocaine in patients with a diagnosis of cocaine dependence. Using a randomized double-blind placebo-controlled design, ecopipam administered to humans 2 hours prior to an intravenous injection of 30 mg of cocaine dose-dependently blocked the subjective effects of cocaine. These doses of ecopipam did not block the effects of cocaine on heart rate or produce any other untoward effects. These are very exciting observations for 2 reasons. First, the results suggest that a dopamine-selective D1 dopaminergic antagonist is effective in humans in blocking the psychotropic effects of cocaine and second, these observations begin to validate a wealth of preclinical data suggesting powerful cocaine antagonistic effects of dopamine D1 antagonists.
Koob GF. Cocaine Reward and Dopamine ReceptorsLove at First Site. Arch Gen Psychiatry. 1999;56(12):1107-1108. doi:10.1001/archpsyc.56.12.1107