Topical beta-blocker therapy and central nervous system side effects. A preliminary study comparing betaxolol and timolol
M. G. Lynch, J. T. Whitson, R. H. Brown, H. Nguyen and M. M. Drake
Department of Ophthalmology, University of Texas Southwestern Medical Center, Dallas.
Topical beta-blocking agents have been associated with adverse central
nervous system (CNS) effects, including depression, emotional lability, and
sexual dysfunction. Two studies were done to determine if patients who
develop CNS effects while using timolol maleate would improve with
betaxolol hydrochloride. In one study, 18 patients with CNS symptoms during
timolol therapy were switched to betaxolol. Sixteen of the 18 patients
noted symptomatic improvement with betaxolol. The second study involved
seven patients with CNS symptoms during timolol therapy who were entered
into a double-masked cross-over study. In two patients CNS symptoms
resolved with betaxolol; in three patients symptoms improved; and in one
patient symptoms worsened with betaxolol. Although factors influencing
beta-blocker activity in the CNS are not well understood, there may be some
advantage to a selective agent.
