Abstract
Abstract: :
Purpose: Previously, Timolol-LA (TLA, ISTALOL), an investigational drug, was reported safe when used topically in humans (Novack et al, ARVO 2002). In the present study, the long-term efficacy and safety of once-daily TLA, a unique formulation of timolol containing potassium sorbate, was compared to twice-daily timolol maleate ophthalmic solution (TIM). Methods: In a double-masked, 12 month study patients with ocular hypertension or open-angle glaucoma were randomized to either 0.5% TLA q.d. (AM) and vehicle q.d. (PM), or 0.5% TIM, b.i.d. Results: The 332 patients were 80% Caucasian, 13% Black and 7% other; 61% female; and 60% aged 65 years or greater. At baseline, the unmedicated mean IOP was 25 mm Hg. Following treatment, the mean IOP in both treatment groups decreased to 19-20 mm Hg at trough (↓5-6 mm Hg, ↓20-24%) and 18-19 mm Hg at peak (↓6-7 mm Hg, ↓24-28%). In the equivalency analysis, at none of the visits did the 95% confidence intervals for between treatment comparisons exceed 1.5 mm Hg, and at most of the visits, the intervals did not exceed 1.0 mm Hg. Adverse events were as expected from a topical ß-blocker, and similar between TLA and TIM, with the exception of a differential incidence of burning and stinging (42% for TLA, 23% for TIM). Nearly all of these events were rated as mild (97% with TLA, 90% with TIM). No patients discontinued study treatment due to burning and stinging. Conclusions: TLA 0.5%, once-daily, was an effective 24-hour ocular hypotensive agent, and equivalent to TIM 0.5%, twice-daily, at both peak and trough through this 12 month study. The ocular and systemic safety of TLA was similar to that of TIM, with the exception of a greater incidence of burning and stinging of mild severity with TLA.
Keywords: pharmacology • intraocular pressure