Mirtazapine is an atypical antidepressant with tetracyclic structure that acts as an antagonist at central presynaptic α2-adrenergic receptors and 5-HT2 and 5-HT3 receptors, which can modulate pain perception and neurotransmitter release. For Cluster Headache, it may help reduce neurogenic inflammation and provide potential prophylactic effects by altering serotonergic and noradrenergic neurotransmission, though its precise mechanism in headache management is not fully elucidated.