Olopatadine hydrochloride (
olopatadine, 11-[(Z)-3-(dimethylamino)propylidene]-6,11-dihydrodibenz[b,e]
oxepin-2-
acetic acid monohydrochloride) is a novel
antiallergic/
histamine H1-receptor antagonistic
drug that was synthesized and evaluated in our laboratories.
Oral administration of
olopatadine at doses of 0.03 mg/kg or higher inhibited the symptoms of experimental allergic skin responses, rhinoconjunctivitis and
bronchial asthma in sensitized guinea pigs and rats.
Olopatadine is a selective
histamine H1-receptor antagonist possessing inhibitory effects on the release of inflammatory
lipid mediators such as
leukotriene and
thromboxane from human polymorphonuclear leukocytes and eosinophils.
Olopatadine also inhibited the tachykininergic contraction in the guinea pig bronchi by prejunctional inhibition of peripheral sensory nerves.
Olopatadine exerted no significant effects on action potential duration in isolated guinea pig ventricular myocytes, myocardium and human
ether-a-go-go-related gene channel.
Olopatadine was highly and rapidly absorbed in healthy human volunteers. The urinary excretion of
olopatadine accounted for not less than 58% and the contribution of metabolism was considerably low in the clearance of
olopatadine in humans.
Olopatadine is one of the few renal clearance drugs in
antiallergic drugs.
Olopatadine was shown to be useful for the treatment of
allergic rhinitis and
chronic urticaria in double-blind clinical trials.
Olopatadine was approved in Japan for the treatment of
allergic rhinitis,
chronic urticaria,
eczema dermatitis,
prurigo,
pruritus cutaneous,
psoriasis vulgaris and
erythema exsudativum multiforme in December, 2000.
Ophthalmic solution of
olopatadine was also approved in the United States for the treatment of seasonal
allergic conjunctivitis in December, 1996 (Appendix: also in the European Union, it was approved in February 2002).