Cyproheptadine

Cyproheptadine, sold under the brand name Periactin among others, is a first-generation antihistamine with additional anticholinergic, antiserotonergic, and local anesthetic properties. Cyproheptadine, sold under the brand name Periactin among others, is a first-generation antihistamine with additional anticholinergic, antiserotonergic, and local anesthetic properties. It was patented in 1959 and came into medical use in 1961. Adverse effects include: Gastric decontamination measures such as activated charcoal are sometimes recommended in cases of overdose. The symptoms are usually indicative of CNS depression (or conversely CNS stimulation in some) and excess anticholinergic side effects. The LD50 in mice is 123 mg/kg and 295 mg/kg in rats. Cyproheptadine is a very potent antihistamine or antagonist of the H1 receptor. At higher concentrations, it also has anticholinergic, antiserotonergic, and antidopaminergic activities. Of the serotonin receptors, it is an especially potent antagonist of the 5-HT2 receptors, and this underlies its effectiveness in the treatment of serotonin syndrome. Cyproheptadine is known to be an antagonist or inverse agonist of all of the receptors listed in the adjacent table. Cyproheptadine has weak antiandrogenic activity. Cyproheptadine is well-absorbed following oral ingestion, with peak plasma levels occurring after 1 to 3 hours. Its terminal half-life when taken orally is approximately 8 hours. Cyproheptadine is a tricyclic benzocycloheptene and is closely related to pizotifen and ketotifen as well as to tricyclic antidepressants.