CHLORCYCLIZINE

Absorption

Readily absorbed after oral administration and widely distributed throughout the body. Metabolised by N-demethylation to form norchlorcyclizine and by N-oxidation.

Originator

Perazil,Burroughs-Wellcome,US,1949

Background

Chlorcyclizine is a first generation phenylpiperazine class antihistamine used to treat urticaria, rhinitis, pruritus, and other allergy symptoms. Chlorcyclizine also has some local anesthetic, anticholinergic, and antiserotonergic properties, and can be used as an antiemetic.

Definition

ChEBI: 1-[(4-chlorophenyl)-phenylmethyl]-4-methylpiperazine is a diarylmethane.

Manufacturing Process

0.08 mol (19 9) of 4-chlorobenzhydryl chloride and 0.16 mol (16 g) of methylpiperazine were mixed in about 20 cc of dry benzene. The flask containing the reaction mixture was covered by a watch glass and set in a steam bath, and heating was continued for 6 hours. The contents of the flask were partitioned between ether and water and the ethereal layer was washed with water until the washings were neutral. The ethereal layer was extracted successively with 30 and 10 cc portions of 3 N hydrochloric acid. On evaporation of the ether layer there remained a residue of 2.5 9. The aqueous extracts were united and basified with concentrated alkali. The oily base was taken into ether and dried over potassium carbonate. On evaporation of the ether, N-methyl-N'-(4-chlorobenzhydryl) piperazine was recovered in the form of a viscous oil in 75% yield. The N-methyl-N'-(4-chlorobenzhydryl) piperazine was dissolved in absolute alcohol and ethanolic hydrogen chloride added in excess. The dihydrochloride crystallized on addition of absolute ether and was recrystallized from the same solvent mixture in the form of longish prisms melting at about 216°C.

brand name

Di-Paralene (Abbott).

Therapeutic Function

Antihistaminic

Metabolism

High concentrations of the N-desmethyl metabolite are found in the liver, lungs, kidney, and spleen.