[Beta-blockers in collyria and their secondary effects]

Beta-blockings in collyrium are much used in ophthalmology, in the treatment of chronic glaucoma with open angle, because they decrease the OT with 25-30%. They are well accepted, but have systemic effects. The collyria are drained by the lacrimal system and 80% of the product is absorbed by the nasal mucosa. If the active substance penetrates into the circulatory system, avoiding hepatic metabolization, it reaches the target organs in a rather considerable amount and leads sometimes to adverse effects, as a consequence of blockage of the specific receptors. Although these effects are not frequent in the usual practice, they might decompensate a poor cardiac or respiratory function. The physician has to take into account the cardio-respiratory state of the patients and to recommend concomitantly drugs that lower the myocardial conduction or contractibility.