A comparison of the efficacy and tolerability of dorzolamide and acetazolamide as adjunctive therapy to timolol. Oral to Topical CAI Study Group.

PURPOSE: To compare the efficacy and tolerability of dorzolamide to acetazolamide.

METHODS

Following a timolol and acetazolamide run-in, 105 patients with elevated intraocular pressure (IOP) were randomized to dorzolamide or acetazolamide, in addition to timolol, for 12 weeks.

RESULTS

More patients receiving acetazolamide discontinued due to clinical adverse experiences than patients receiving dorzolamide; 13 (25%) vs. 1 (2%); p<0.001. The prevalence of systemic adverse experiences for the dorzolamide group dropped by 50% by Week 12, but remained unchanged for the acetazolamide group, as compared to baseline; p<0.001. Ocular burning/stinging was more common in the dorzolamide group (21% vs. 0%; p<0.001). The mean trough IOP at Day 1 and Week 12 were 20.5 mmHg and 21.8 mmHg for the dorzolamide group, and 20.4 mmHg and 20.5 mmHg for the acetazolamide group. The mean peak IOP at Dayl and Week 12 were 18.9 mmHg and 20.0 mmHg for the dorzolamide group, and 18.7 mmHg and 18.6 mmHg for the acetazolamide group.

CONCLUSIONS

Mean IOP was slightly lower (by approximately 1 mmHg) with acetazolamide, while dorzolamide demonstrated much better tolerability.