Other receptor acting drugs and receptors

Clozapine, a drug with significant D4 and 5-HT2 receptor-blocking actions,D1, muscarinic, and α-adrenergic receptors, but it is also a weak dopamine D2-receptor antagonist. Most of the newer atypical drugs (eg, olanzapine, quetiapine, and risperidone) also have high affinity for 5-HT2A receptors, although they may also interact with D2 and other receptors.Ziprasidone is an antagonist at the D2, 5-HT2A, and 5-HT1D receptors and an agonist at the 5-HT1A receptor. The newer antipsychotic agent aripiprazole is a partial agonist at D2 and 5-HT1A receptors but is a strong antagonist at 5-HT2A receptors. Quetiapine blocks D2 receptors more potently than 5HT2A receptors but is relatively weak at blocking either receptor, and its low risk for EPS may also be related to the relatively short period of time it binds to the D2 receptor.