“May all be happy, may all be healed, may all be at peace and may no one ever suffer."
Antazoline is an anti-histamine of the ethylenediamine class, which are selective HI-antagonist. Effects mediated by HI receptors include the contraction of smooth muscle and the dilation and increased permeability of the capillaries. Tetryzoline is a sympathomimetic with alpha-adrenergic activity. Its vasoconstrictive effect reduces redness and edema in allergic conjunctivitis. Antihistamines, which act by blocking the HI histamine receptor, are highly effective in providing relief of itching but are not very active in relieving the associated redness. The use of products combining an anti-histamine and a vasoconstrictor is well established in the symptomatic relief of allergic eye disease.