A COMPARISON OF THE OCULAR TOLERABILITY OF A SINGLE-DOSE OF TIMOLOL AND LEVOBUNOLOL IN HEALTHY NORMOTENSIVE VOLUNTEERS

Subject acceptance of a single dose of timolol and levobunolol was com pared in a three-center, double-masked, randomized, crossover study in healthy normal subjects. We tested 115 subjects who received the medi cations OU, in a random order, separated by a washout period of three to seven days. At the end of the administration, the subjects were ask ed to report any symptoms and were monitored by ophthalmologic examina tion. Those receiving levobunolol reported a two- to threefold higher frequency of symptoms than did those receiving timolol (P = .0002, by Mainland-Gart chi-square test). Thirty-five subjects (30.4%) treated w ith levobunolol complained of burning versus 14 (12.2%) receiving timo lol (P = .0021). Similar results were obtained in regard to stinging ( 31 versus 10 subjects; P = .0011). The duration of these symptoms did not differ between the two groups (P > .05). Timolol induced considera bly less burning and stinging on day 1 compared with levobunolol, usin g a visual analog scale over time (P = .0004). Seventy-nine percent of those stating a preference chose timolol (P < 3 x 10(-9)).