MK-927: a topical carbonic anhydrase inhibitor. Dose response and duration of action
E. J. Higginbotham, M. A. Kass, E. A. Lippa, R. L. Batenhorst, D. L. Panebianco and J. T. Wilensky
Department of Ophthalmology, University of Illinois, Chicago 60612.
The dose response to a single topical administration of the carbonic
anhydrase inhibitor MK-927 was investigated in 24 patients with primary
open angle glaucoma or ocular hypertension. Three concentrations of MK-927
(2%, 1%, and 0.5%) and placebo were administered in a two-center,
double-masked, randomized, placebo-controlled, four-period crossover study.
MK-927 at the 0.5% concentration appeared to be minimally effective in
reducing intraocular pressure. A single topical dose of 1% MK-927 resulted
in a significantly greater percent reduction in intraocular pressure for up
to 6 hours when compared with treatment with placebo. Similarly, a single
dose of 2% MK-927 significantly lowered intraocular pressure for 8 hours
compared with treatment with placebo. The pressure reduction from baseline
measured 23.7% and 11.3% at 8 hours after instillation of a single drop of
2% MK-927. The medication was well tolerated and appeared to lower
intraocular pressure in a dose-dependent fashion.
