EFFECTS OF NEW CLONIDINE DERIVATIVES ON RABBIT INTRAOCULAR-PRESSURE

Effects of 25 topically applied clonidine derivatives on rabbit IOP recovery model using intravenous hypertonic saline were studied. Among them, 12 compounds were dissolved in aqueous medium, 11 compounds in polyethylene glycol (PEG 200) and 2 compounds in dimethyl sulfoxide (DMSO). Four compounds showed marked delay in IOP recovery and were more active than S-timolol and clonidine. Five compounds were about equiactive to S-timolol and more active than clonidine in suppression of IOP recovery and prolongation of the duration of drug action. There were three compounds that were less active than S-timolol yet they were still as active or were active than clonidine. Thirteen out of 25 compounds were inactive in suppressing IOP recovery curves. Most of these active compounds (9 out of 12) suppressed IOP recovery in the same magnitude for both treated and non-treated contralateral eyes, indicating that these effects were manifested though central actions. Three out of 12 compounds showed more effect with treated eyes than with non-treated contralateral eyes, indicating that the local effects were predominant.