Cardiovascular Effects of Topical Glaucoma Therapies in Normal Subjects

Abstract

Topical glaucoma therapies may induce adverse systemic side effects. This study was designed to determine the potential for drug-induced cardiovascular side effects of various glaucoma therapies applied topically to the eye. Data from three short-term double-blind studies in a total of 19 normal healthy adult volunteers were used to discriminate potential cardiovascular side effects. Baseline pulse rates and blood pressures were measured before and after exercise. Subsequent measurements were made 3 hr after topical ocular treatment with two drops of each glaucoma medication. Each individual was used to test each glaucoma therapy after washout of a 1 week period between treatments. The therapies included an alpha agonist (ALO 2145), three beta-blockers (betaxolol, bunolol, and timolol), and a placebo. No drug related pre- and post-exercise mean arterial pressure changes were observed. However, the two nonselective beta-blockers, timolol (0.5%) and bunolol (1%), consistently decreased the resting and/or exercise pulse rate, while the beta-1 selective blocker, betaxolol, did not. ALO 2145, the alpha agonist, did not alter the pulse rate or mean arterial pressure. Thus, some glaucoma therapies have the potential to reduce the heart rate especially under stress situations.