[Experimental studies with timolol: a new ocular hypotensive agent (author's transl)]

The present report reviews the animal pharmacology supporting the clinical use of timolol maleate ophthalmic solution in the therapy of glaucoma and elevated intraocular pressure (IOP). The studies have included the effects of timolol upon normal IOP of rabbits and upon elevated IOP in two models of experimental ocular hypertension. Comparisons are made between the latter actions of timolol and those of the reference adrenergic antiglaucoma agent, epinephrine. The interaction of timolol and the beta-adrenergic stimulant, isoproterenol, was also studied to assess the ability of timolol to block beta-adrenergic receptors in the eye. Additionally, the penetration and distribution of timolol in ocular and extraocular tissues and fluids following local application to the eyes of rabbits is described and a resume of the toxicological studies with timolol are presented.