Atiprosine (AY-28228) is an orally effective selective alpha1-adrenergic receptor antagonist with a pA2 value of 8.11. Atiprosine exhibits antagonistic activity against alpha2-adrenergic receptors (alpha1-adrenergic receptor), 5-HT2 receptors (5-HT2 receptor), and H1 receptors (H1 receptor). The pA2 values for these receptors are 6.04, 6.87, and 7.32 respectively. Atiprosine has antihypertensive and hypotensive effects in rats, dogs, and monkeys. It can be used for research on cardiovascular and mental disorders.