The Influence of Topical Diclofenac Sodium on the Ocular Hypotensive Effect of Latanoprost in Glaucoma Patients

Purpose: To evaluate the effect of diclofenac sodium 0.1% on reducing intraocular pressure (IOP) by latanoprost 0.005% in glaucoma patients. Patients and Methods: Twenty-two patients with bilateral primary open angle glaucoma were enrolled in this study. All patients had been given only latanoprost for at least 4 weeks. Topical diclofenac sodium was additionally applied to one eye (dicloptin group), whereas hydroxypropyl methyl cellulose was administered into the other eye (control group); both 4 times a day for 2 weeks. IOP measurement was performed before and 2 weeks after the administrations, and also 2 weeks after discontinuing additional ophthalmic solutions. Results: No significant difference was observed in the IOPs before additional administration of ophthalmic solution between the dicloptin group and the control group (P = 0.47). Additional administration of diclofenac sodium increased mean IOP from 15.73 +/- 1.75 to 17.32 +/- 2.23mm Hg (P = 0.01). This increase was reversed 2 weeks after discontinuing additional solutions (P = 0.80); however, no significant difference in mean IOP was observed in the control group after administration and after discontinuing the additional medication (P = 0.94 and 0.84, respectively). Conclusions: Topical diclofenac sodium may interfere with the IOP lowering effect of latanoprost in glaucoma patients; therefore this interference should be noted in coadministration of these drugs.