Effect of non-steroidal anti-inflammatory ophthalmic solution on intraocular pressure reduction by latanoprost

Aim: To investigate the effects of a non-steroidal anti-inflammatory drug (NSAID) ophthalmic solution on latanoprost induced intraocular pressure (IOP) reduction using normal volunteers. Methods: This study was conducted as a prospective and observer masked clinical trial. 13 normal volunteers were enrolled. After measurement of basal IOP and ophthalmic examination, latanoprost ophthalmic solution was initially administered to both eyes once daily. Four weeks later, an NSAID ophthalmic solution, sodium 2-amino-3-(4-bromobenzoyl) phenylacetate sesquihydrate (refer to bromfenac sodium hydrate), was co-administered to one randomly selected eye (NSAID group) twice daily for 2 weeks. The other eye was employed as a control (non-NSAID group). After withdrawal of the NSAID ophthalmic solution, latanoprost ophthalmic solution was continuously administered for another 2 weeks and was then withdrawn. After a 4 week washout, only bromfenac sodium hydrate ophthalmic solution was administered to the eyes of the NSAID group for 2 weeks. During the study period, ophthalmic examination, including IOP measurement was performed in an observer masked fashion. Results: Before initiation of bromfenac sodium hydrate, baseline IOPs of the non-NSAID group and the NSAID group were 15.73 (SD 1.97) mm Hg and 15.86 (2.06) mm Hg, respectively (p=0.88). Although latanoprost ophthalmic solution significantly reduced IOP in both groups, co-administration of bromfenac sodium hydrate significantly inhibited latanoprost induced IOP reduction compared with the non-NSAID group. The IOPs of the non-NSAID and NSAID groups were 10.18 (1.17) mm Hg and 11.63 (1.35) mm Hg with a 2 week co-administration, respectively (p <0.01). Withdrawal of bromfenac sodium hydrate ophthalmic solution diminished the difference between the two groups. Re-administration of bromfenac sodium ophthalmic solution only did not affect IOP. Conclusion: These results indicate that NSAID ophthalmic solution may interfere with IOP reduction by latanoprost ophthalmic solution in normal volunteers and that we should take this into account when treating patients with glaucoma using latanoprost ophthalmic solution.