A 90-day study of the efficacy and side effects of 0.25% and 0.5% apraclonidine vs 0.5% timolol. Apraclonidine Primary Therapy Study Group
W. C. Stewart, R. Laibovitz, B. Horwitz, R. H. Stewart, R. Ritch and M. Kottler
Pharmaceutical Research Corporation, Charleston, SC, USA.
OBJECTIVE: To compare long-term intraocular pressure (IOP)-lowering
efficacy of 0.25% and 0.5% apraclonidine hydrochloride with 0.5% timolol
maleate. DESIGN: Multicenter, randomized, double-masked trial. Adult
patients of either sex diagnosed as having open-angle glaucoma or ocular
hypertension were enrolled following appropriate washout from all ocular
hypotensive medications. Morning IOPs of 22 to 35 mm Hg were required for
entry. Patients received 0.25% or 0.5% apraclonidine 3 times a day or 0.5%
timolol twice a day for 90 days. Intraocular pressure was measured at 8 AM
(before morning dosing) and at 4 PM (8 hours after dosing) on days 1, 30,
and 90, and only at 8 AM on day 14. RESULTS: All 3 medications
significantly reduced IOP from baseline at all observation times (P <
.001): 0.5% apraclonidine reduced IOP more than 0.25% apraclonidine; no
significant difference was observed between 0.5% apraclonidine and 0.5%
timolol 8 hours after dosing on days 1, 30, and 90; and a significant
difference (P < .05) in favour of 0.5% timolol over 0.25% apraclonidine
was observed 8 hours after dosing on day 30. At all morning visits
following evening dosing, 0.5% timolol significantly reduced IOP more than
both concentrations of apraclonidine. CONCLUSIONS: Both 0.25% and 0.5%
apraclonidine significantly reduce IOP when used as primary ocular
hypotensive medication. Although 0.25% and 0.5% apraclonidine reduce IOP to
a similar degree as 0.5% timolol 8 hours after morning dosing, neither
concentration is as effective for reducing morning IOP after evening
dosing.
