Naphazoline hydrochloride is an adrenergic vasoconstrictor agent used as a decongestant. Naphazoline hydrochloride is the hydrochloride salt form of naphazoline, an imidazole derivative and a direct-acting sympathomimetic amine with vasoconstrictive properties. Upon ocular administration, naphazoline hydrochloride exerts its effect by acting on alpha- adrenergic receptors in the arterioles of the conjunctiva to produce vasoconstriction, resulting in decreased conjunctival congestion and diminished itching, irritation and redness.