The phenothiazines are also antagonists at α1 adrenergic receptors, histamine H1 receptors, muscarinic cholinergic receptors and serotonin 5-HT2 receptors, explaining a number of prominent '''side effects''', including decreased hematocrit (α1 adrenoceptors in the splenic capsule), decreased total peripheral resistance (hypotension, α1 adrenoceptors in the vasculature) and penile prolapse (priapism). Hypotension can be profound, particularly in animals with high levels of circulating catecholamines (stress). | The phenothiazines are also antagonists at α1 adrenergic receptors, histamine H1 receptors, muscarinic cholinergic receptors and serotonin 5-HT2 receptors, explaining a number of prominent '''side effects''', including decreased hematocrit (α1 adrenoceptors in the splenic capsule), decreased total peripheral resistance (hypotension, α1 adrenoceptors in the vasculature) and penile prolapse (priapism). Hypotension can be profound, particularly in animals with high levels of circulating catecholamines (stress). |