Practolol (Eraldin) eye drops as an ocular hypotensive agent.

It has been demonstrated that propranolol has the ability to lower the ocular tension in patients with glaucoma when given by intravenous injection (Phillips, Howitt, and Rowlands, I967; Vale and Phillips, 1970), when applied topically (Bucci, Giraldi, Pecori, Missiroli, and Virno, I968; Vale, Gibbs, and Phillips, 1972), or when given orally (Phillips and others, I967; Cot6 and Drance, I968). However, the topical use of pro- pranolol has a possible disadvantage in that it produces local anaesthesia. (Propranolol also possesses membrane activity which is in part responsible for its action against cardiac arrhythmias. The local anaesthesia and membrane activity are distinct from the ,B- receptor blocking properties.) For this reason the effects of other n-receptor antagonists on ocular tension are being investigated. The one selected for this study was practolol (Eraldin). It is a compound having no local anaesthetic or anti-arrhythmic properties but capable of blocking cardiac 0-adrenergic receptors in doses which have no effect on other 3-receptors (Dunlop and Shanks, I968). Cardiac n-receptors are those designated as 01 by Lands, Arnold, McAuliff, Ludena, and Brown (I967). ( Other receptors desig-