• Prazosin hydrochloride, a systemic antihypertensive agent, lowers intraocular pressure when applied topically to normal rabbit eyes. A 0.01% solution of topically administered prazosin did not alter outflow facility, episcleral venous pressure, systemic blood pressure, or ocular blood flow. Tonography suggested a 27% decrease in the rate of aqueous humor formation two hours following topical administration. Posterior chamber aqueous ascorbate levels were increased following topical administration of prazosin, which also suggested a decreased entry rate of water into the eye. The effect of prazosin on IOP was prevented by systemic pretreatment with phentolamine mesylate, an α-adrenergic blocking agent, but not by propranolol hydrochloride or atropine sulfate. This was consistent with the known action of prazosin as a postsynaptic αadrenergic blocking agent.
Krupin T, Feitl M, Becker B. Effect of Prazosin on Aqueous Humor Dynamics in Rabbits. Arch Ophthalmol. 1980;98(9):1639-1642. doi:10.1001/archopht.1980.01020040491021