Source:http://linkedlifedata.com/resource/umls/id/C0304657
NCI: The hydrochloride salt form of apraclonidine, a clonidine derivative with selective alpha-2-adrenergic agonistic property. When administered directly to eyes, apraclonidine hydrochloride enhances aqueous humor outflow and decreases aqueous production by vasoconstriction. It is used mostly in ophthalmic preparations for decreasing intraocular pressure.