Morphine eye-drops reduce homatropine induced mydriasis in man.
In 7 healthy volunteers 4% morphine eye-drops, when administered to one eye, caused a miosis limited to that eye. In 7 other healthy volunteers morphine was administered into one eye after bilateral instillation of 0.5% homatropine ophthalmic drops; the eye treated with morphine and homatropine showed a mydriasis less intense than the other eye treated only with homatropine. It is suggested that topical morphine locally affects sympathetic function by inhibiting noradrenaline release into the iris neuromuscular junction.
D005260:Female; D006801:Humans; D007498:Iris / Q000187:drug effects; D008297:Male; D008875:Middle Aged; D009020:Morphine / Q000494:pharmacology*; D009469:Neuromuscular Junction / Q000187:drug effects; D011680:Pupil / Q000187:drug effects*; D014326:Tropanes / Q000037:antagonists & inhibitors*
D014326:Tropanes; D009020:Morphine; C100236:homatropine