Effect of adrenaline and guanethidine in reducing intraocular pressure in rabbits' eyes

The effect of Adrenaline 0.5 per cent and Guanethidine 2.5 per cent alone and in combination in reducing intraocular pressure in rabbits has been studied. Six rabbits were used and the efficiencies of 5 different dosage protocols was estimated both as intensity and duration of activity. The 5 dosage protocols were Adrenaline alone; Guanethidine alone; Adrenaline and Guanethidine together; Adrenaline followed in 30 min by ?Guanethidine; and Guanethidine followed in 30 min by Adrenaline. The single formulation containing both drugs appeared to be at least as efficient as the others. Eye drops containing 1 per cent Adrenaline and 5 per cent Guanethidine having sufficient stability for normal use have therefore been formulated.