3546-03-0

Cyamemazine exhibits a high affinity for dopamine receptors, which is consistent with its antipsychotic activity. The antagonist activity of Cyamemazine at muscarinic receptors is consistent with its affinity for M ₁ ( K _i = 13 nM), M ₂ ( K _i = 42 nM), M ₃ ( K _i = 321 nM), M ₄ ( K _i = 12 nM), and M ₅ ( K _i = 35 nM) receptors.

Cyamemazine behaves as an antagonist at the 5-HT ₃ , 5-HT _2C , and 5-HT _2A receptors in 5-HT ₃ -dependent contraction of isolated guinea pig ileum and bradycardic responses in rats, in 5-HT _2C -dependent phospholipase C stimulation in the rat brain membrane, and in 5-HT _2A -dependent contraction of isolated rat aorta rings and isolated guinea pig trachea. Cyamemazine antagonizes 5-HT ₃ and 5-HT _2C receptors and that this effect is partially involved in its therapeutic activity in anxiety disorders. Acute administration of low doses of Cyamemazine can reduces extracellular dopamine and metabolite concentrations in rat striatum.