On the anticataleptic action of cyproheptadine

The anticataleptic action of cyproheptadine, a tricyclic compound known as antiserotonin, anticholinergic and antihistaminic drug in comparison to that of atropine, promethazine, imipramine, desipramine, chlorimipramine and nomifensine was studied in rats. The catalepsy induced by spiperon, pimozide or fluphenazine was antagonized by cyproheptadine, atropine and promethazine. Imipramine and nomifensine were less active, desipramine and chlorimipramine without effect. The reserpine- and alpha-methyltyrosine-catalepsy was counteracted by cyproheptadine, promethazine and nomifensine, but not by atropine or tricyclic antidepressants. Only cyproheptadine and promethazine antagonized the catalepsy caused by a combined treatment with reserpine and alpha-methyltyrosine. The pilocarpine-catalepsy was abolished by atropine, promethazine and nomifensine and unaffected by tricyclic antidepressants. Atropine and promethazine antagonized also the physostigmine-catalepsy. The catalepsy induced by both cholinomimetic drugs was not changed or increased by cyproheptadine. The results presented indicate that cyproheptadine differs in its anticataleptic activity from all the drugs used for comparison. Possible mechansims of this activity are discussed.