INTERACTION OF PHXA41, A NEW PROSTAGLANDIN ANALOG, WITH PILOCARPINE - A STUDY ON PATIENTS WITH ELEVATED INTRAOCULAR-PRESSURE

Objective.-To evaluate the effects of PhXA41, a new prostaglandin analogue, on the intraocular pressure (IOP) in patients receiving pilocarpine treatment and the effects of pilocarpine in patients receiving PhXA41 treatment. Design.-Twenty patients with ocular hypertension were randomized into two parallel groups. The treatment period was 2 weeks. Ten patients in group 1 were given PhXA41 twice daily during week 1 and, in addition, pilocarpine three times daily during week 2. Ten patients in group 2 received pilocarpine three times daily during week 1 and PhXA41 twice daily in addition during week 2. PhXA41 was used in a concentration of 0.006%, and pilocarpine was given in a concentration of 2%. Main Outcome Measures.- In group 1, the mean IOP on day 0 was 25.1 mm Hg; on day 7,19.1 mm Hg; and on day 14,17.6 mm Hg. In group 2, the mean IOP on day 0 was 23.8 mm Hg; on day 7,20.4 mm Hg; and on day 14,17.7 mm Hg. Results.-PhXA41 had a clinically significant IOP-lowering effect (23.4% reduction on day 7 as compared with baseline day (P<.001). The corresponding value with pilocarpine was 14.3% (P<.001). When pilocarpine was added to PhXA41, the additional IOP reduction was 7.4% (P<.01) compared with 14.2% (P<.01) when PhXA41 was added to pilocarpine. The two groups were found to have an almost equal reduction in IOP on day 14 (group 1, 29.4%; group 2, 26.6%). No serious adverse reactions were seen. Some conjunctival hyperemia in the PhXA41-treated eyes was noted on day 7, as compared with the pilocarpine-treated eyes, but there were few complaints of discomfort. Conclusions.-This study indicated that PhXA41 could be useful in the treatment of glaucoma, as monotherapy, or in certain cases in combination with pilocarpine.