Clemastine fumarate belongs to the benzhydryl ether accumulation of antihistaminic compounds. The actinic name is (+)-2-[-2- [(p-chloro-α-methyl-α-phenylbenzyl) oxy] ethyl]-1-methylpyrrolidine hydrogen fumarate.
Clemastine fumarate is an antihistamine with anticholinergic (drying) and allaying ancillary effects. Antihistamines arise to attempt with histamine for corpuscle receptor sites on effector cells. The inherently continued continuance of antihistaminic furnishings of clemastine has been approved in abscess and blaze studies. In accustomed animal capacity who accustomed histamine injections over a 24-hour period, the antihistaminic action of clemastine accomplished a aiguille at 5 to 7 hours, persisted for 10 to 12 hours and, in some cases, for as continued as 24 hours. Pharmacokinetic studies in man utilizing 3H and 14C labeled admixture demonstrates that: clemastine is rapidly and about absolutely captivated from the gastrointestinal tract, aiguille claret concentrations are accomplished in 2 to 4 hours, and urinary abolishment is the above approach of elimination.