A-77636 is a synthetic drug which acts as a selective D₁ receptor full agonist. It has nootropic, anorectic, rewarding and antiparkinsonian effects in animal studies, but its high potency and long duration of action causes D₁ receptor downregulation and tachyphylaxis, and unlike other D₁ full agonists such as SKF-82,958, it does not produce place preference in animals. A-77636 partially substituted for cocaine in animal studies, and has been suggested for use as a possible substitute drug in treating addiction, but it is better known for its use in studying the role of D₁ receptors in the brain.