Interaction of PhXA41, a new prostaglandin analogue, with pilocarpine. A study on patients with elevated intraocular pressure
B. Fristrom and S. E. Nilsson
Department of Ophthalmology, University of Linkoping, Sweden.
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.
