Twenty-four-hour efficacy of the brimonidine/timolol fixed combination versus therapy with the unfixed components

To evaluate the 24-h intraocular pressure (IOP) control of brimonidine/timolol fixed combination (BTFC) versusthe unfixed combination of its individual components, each dosed twice daily, in patients with primary open-angle glaucoma or ocular hypertension.

An observer-masked, randomized, crossover, active-controlled, two-centre comparison. Following a 6-week medicine-free period, patients were randomized to BTFC or to the unfixed combination of brimonidine and timolol for 3 months. Patients then were crossed over to the opposite treatment for another 3 months. At the end of the medicine-free period, and each treatment period, patients underwent 24-h IOP measurements at 0600, 1000, 1400, 1800, 2200, and 0200 hours.

Twenty-eight patients completed this study. Both BTFC and the unfixed components showed a significant IOP reduction from untreated baseline (P<0.0001), and were statistically equal when compared directly, for each individual time point and for the 24-h IOP curve (P>0.05). The mean 24-h IOP was 24.6+/-1.9 for baseline, 19.2+/-1.9 for BTFC, and 19.2+/-1.6 mmHg for the unfixed components (P=1.0). Four patients were discontinued due to side effects. The most common ocular adverse event was ocular hyperaemia (n=3 with BTFC and n=5 with the unfixed components, P=0.7) and systemic adverse events were rare.

This study suggests that both BTFC and the unfixed components of brimonidine and timolol provide a significant 24-h IOP reduction from untreated baseline, and statistically equal control when compared directly, at each time point and for the 24-h pressure curve.