Epinastine (hydrochloride)

Epinastine is a histamine H₁ receptor antagonist (apparent K_is = 1.41 and 1.62 nM using guinea pig cerebellar and lung membranes, respectively) and mast cell stabilizer.^1,2 It inhibits IgE-induced histamine, TNF-α, and IL-10 secretion in human cord blood stem cell-derived mast cells (CBMCs) when used at a concentration of 0.1 μg/ml.² Epinastine inhibits histamine-induced cutaneous vascular permeability in rats and bronchoconstriction in anesthetized guinea pigs (ID₅₀s = 5 and 0.1 mg/kg, respectively).³ It inhibits dye leakage into the conjunctiva in a rat model of passive anaphylaxis reaction-induced vascular hyperpermeability of the conjunctiva (ID₅₀ = 9.7 mg/kg, p.o.).⁴ Topical administration of formulations containing epinastine (0.05% three times per day) reduces lid edema, tearing, and redness, as well as the number of neutrophils and eosinophils in the lid fornix, in a mouse model of atopic conjunctivitis.² Formulations containing epinastine have been used in the prevention of itching associated with allergic conjunctivitis.

WARNING This product is not for human or veterinary use.

1. Ter Laak, A.M., Donné-Op den Kelder, G.M., Bast, A., et al. Is there a difference in the affinity of histamine H₁ receptor antagonists for CNS and peripheral receptors? An in vitro study. Eur. J. Pharmacol. 232(2-3), 199-205 (1993).

2. Galatowicz, G., Ajayi, Y., Stern, M.E., et al. Ocular anti-allergic compounds selectively inhibit human mast cell cytokines in vitro and conjunctival cell infiltration in vivo. Clin. Exp. Allergy 37(11), 1648-1656 (2007).

3. Matsushita, K., Nobutoshi, A., and Aritake, K. Pharmacological studies on the novel antiallergic drug HQL-79: II. Elucidation of mechanisms for antiallergic and antiasthmatic effects. Jpn. J. Pharmacol. 78(1), 11-22 (1998).

4. Tamura, T., Sato, H., Miki, I., et al. Effects of orally administered olopatadine hydrochloride on the ocular allergic reaction in rats. Allergol. Int. 52(2), 77-83 (2003).