Ocular hypotensive effect of atenolol (Tenormin, I.C.I.). A new beta-adrenergic blocker

Atenolol (Tenormin or I.C.I. 66082) is a new beta-adrenergic blocking drug, unique in being cardio-selective and in having no intrinsic sympathomimetic or membrane activity. In a controlled double-blind study, a single 50 mg oral dose produced a significant fall in ocular tension for about 7 hours in five patients with definite or suspected glaucoma. The average maximum fall was 35 per cent of the initial pressure; it occurred at 5 hours after oral ingestion. Accordingly neither intrinsic sympathomimetic nor membrane activity can account for all the ocular hypotensive effect of beta blockers in humans. The practical implications for treatment of glaucoma require longer-term investigations some of which are in progress.