Ecopipam (SCH 39166) hydrochloride is a highly potent, selective, and orally active antagonist of dopamine D1/D5 receptors. It exhibits impressive binding affinities, with Ki values of 1.2 nM and 2.0 nM for D1 and D5 receptors, respectively. Ecopipam hydrochloride demonstrates remarkable selectivity, displaying over 40-fold selectivity compared to D2, D4, 5-HT, and α2a receptors, with Ki values of 0.98 μM, 5.52 μM, 0.08 μM, and 0.73 μM, respectively. Its application extends to various areas of research, including schizophrenia, cocaine addiction, and obesity [1] [3].

D 4 Receptor:5520 nM (Ki), D 2 Receptor:980 nM (Ki), D5 receptor:2.0 nM (Ki), D1 receptor:1.2 nM (Ki), α2A-adrenoceptor:731 nM (Ki), 5-HT receptor:80 nM (Ki)

Ecopipam (2 μM) hydrochloride completely abolishes the proconvulsive effect of Dopamine (10 μM) in isolated corticohippocampal formation [2].

Ecopipam (0.003-0.3 mg/kg, a single s.c.) hydrochloride abolishes Nicotine-induced enhancement of a sensory reinforcer in adult rats [3]. Ecopipam (10, mg/kg, oral administration) hydrochloride antagonizes Apomorphine-induced stereotypy in rats [4]. Ecopipam (5 and 10 μM, perfusion, 1 μL/min) hydrochloride reversibly and dose-dependently decreases acetylcholine release in the rat striatum [5]. Animal Model: Male young adult Long-Evans rats injected with Nicotine [3] Dosage: 0.003, 0.01, 0.03, 0.1, 0.3 mg/kg Administration: A single s.c. 20 min before Nicotine (0.1 mg/kg) Result: Dose-dependently reduced pressing on both active and inactive levers.