For the treatment of rhinitis, urticaria, allergy, common cold, asthma and hay fever.
Chlorpheniramine binds to the histamine H1 receptor. This blocks the action of endogenous histamine, which subsequently leads to temporary relief of the negative symptoms brought on by histamine.
LD<sub>50</sub> = 306 mg/kg in humans, mild reproductive toxin to women of childbearing age.
Well absorbed in the gastrointestinal tract.
21-27 hours