Pizotifen

Pizotifen is a benzocycloheptathiophene derivative, specifically 9,10-dihydro-4H-benzo[4,5]cyclohepta[1,2-b]thiophene-4-ylidene-1-methylpiperidine. It forms a double bond between the 4-position of the thiophene ring and the 4-position of an N-methylpiperidine moiety. It is a sedating antihistamine with strong serotonin antagonist activity and weak antimuscarinic effects. It is commonly used as the malate salt for migraine treatment and prophylaxis of cluster headaches. It functions as a serotonergic, muscarinic, and histamine antagonist. It is structurally related to a piperidine and acts as the conjugate base of pizotifen(1+).