Fig. 2
From: Cinnarizine- and flunarizine-associated movement disorder: a literature review
Schematic diagram of the mechanism of action of cinnarizine and flunarizine (CFNZ). CFNZ can act in the vascular smooth muscle blocking the complex calcium-calmodulin (CaM), which will inhibit muscle contraction. In the central nervous system, CFNZ has six main actions; blockage of dopamine D2, histamine H1, and serotonin receptors. Also, it can inhibit the tyrosine hydroxylase and CaM decreasing the synthesis and release of dopamine. Moreover, depending on the site of action, CFNZ can increase serotonin concentration inhibiting serotonin reuptake (SERT) and facilitating serotonin release