title: Influence of thymoxamine eye-drops on the mydriatic effect of tropicamide and phenylephrine alone and in combination.
abstract: In a preliminary experiment in 12 healthy volunteers, one drop of thymoxamine 0.5% instilled into the conjunctival sac completely reversed the mydriasis produced by phenylephrine 2.5%, 5% and 10% after 20 minutes. In a second study in eight volunteers, thymoxamine 0.5% completely prevented the mydriasis produced by phenylephrine 2.5% and produced a miosis. It also completely reversed the mydriasis produced by tropicamide 0.5%. The mydriatic effect of tropicamide 0.5% plus phenylephrine 2.5%, however, was not completely reversed by thymoxamine 0.5% over a period of 180 minutes. Phenylephrine, tropicamide and thymoxamine are freely available for use by registered optometrists.
authors.affiliation: City University, Applied Vision Research Centre, London, UK.
authors.forename: B
authors.initials: B
authors.lastname: Shah
authors.forename: B
authors.initials: B
authors.lastname: Hubbard
authors.forename: J H
authors.initials: JH
authors.lastname: Stewart-Jones
authors.forename: D F
authors.initials: DF
authors.lastname: Edgar
authors.forename: P
authors.initials: P
authors.lastname: Turner
mesh_terms: D000293:Adolescent; D000328:Adult; D004311:Double-Blind Method; D004338:Drug Combinations; D006801:Humans; D008297:Male; D013948:Moxisylyte / Q000494:pharmacology*; D009883:Ophthalmic Solutions; D010656:Phenylephrine / Q000037:antagonists & inhibitors*; D011680:Pupil / Q000187:drug effects*; D011725:Pyridines / Q000037:antagonists & inhibitors*; D011897:Random Allocation; D014331:Tropicamide / Q000037:antagonists & inhibitors*
chemical_list: D004338:Drug Combinations; D009883:Ophthalmic Solutions; D011725:Pyridines; D010656:Phenylephrine; D014331:Tropicamide; D013948:Moxisylyte