Prostaglandin E2 inhibition and aqueous concentration of ketorolac 0.4% (acular LS) and nepafenac 0.1% (nevanac) in patients undergoing phacoemulsification.

PURPOSE: To determine the prostaglandin E(2) (PGE(2)) levels and aqueous concentrations achieved with ketorolac 0.4% (Acular LS; Allergan, Inc, Irvine, California, USA) and nepafenac 0.1% (Nevanac; Alcon Laboratories, Inc, Fort Worth, Texas, USA). DESIGN: Single-center, randomized, double-masked study. METHODS: One hundred and thirty-two patients received ketorolac or nepafenac four times daily for two days before cataract extraction. Aqueous samples obtained at surgery were analyzed for PGE(2) levels (competitive enzyme immunoassay) and drug concentrations. RESULTS: More ketorolac eyes than nepafenac eyes had PGE(2) levels less than the level of detection (<100 pg/ml; 26/42 [61.9%] and 7/40 [17.5%], respectively; P < .001). Mean PGE(2) levels in ketorolac eyes were lower than that in nepafenac eyes (159.5 +/- 114.66 pg/ml and 322 +/- 197.8 pg/ml, respectively; P < .001). The mean aqueous level was 1079.1 +/- 881.5 ng/ml with ketorolac and 353.4 +/- 126.0 ng/ml with amfenac. The nepafenac eyes exhibited 588.4 +/- 394.6 ng/ml of the inactive nepafenac molecule (P < .001 vs ketorolac). CONCLUSIONS: Ketorolac 0.4% inhibited PGE(2) and penetrated into aqueous significantly more than nepafenac 0.1%.