Effects of dapiprazole on pupillary size and intraocular pressure in rabbits

The effects of 3-[2-[4-(2-methylphenyl)-1- piperazinyl]ethyl]-5,6,7,8-tetrahydro-1,2,4-triazolo[4,3-a]pyridine HCl (dapiprazole), a new drug with alpha-adrenergic blocking properties, on pupillary diameter and intraocular pressure have been studied in rabbits. Following i.v. administration, a reduction of intraocular pressure is observed at doses devoid of activity on pupillary diameter. Following topical application, a miotic and ocular hypertensive action was observed at the same doses; the hypotensive action is produced in both normal rabbits and in rabbits with water load- or corticosteroid-induced ocular hypertension. Contact lenses increase the duration of effects of dapiprazole. These results suggest a potential interest of dapiprazole in glaucoma, with particular reference to the topical treatment of angle-closure glaucoma.