Surgeons perform an estimated three million cataract surgeries annually in this country. To help reduce inflammation following ophthalmic surgery, eye care professionals commonly prescribe nonsteroidal anti-inflammatory drugs (NSAIDs) and corticosteroids.
The Food & Drug Administration recently approved nepafenac ophthalmic suspension (Nevanac, Alcon Laboratories) for the treatment of pain and inflammation associated with cataract surgery. Alcon expects Nevanac suspension to be commercially available in the next several weeks.
"Nepafenac is a nonsteroidal anti-inflammatory and analgesic prodrug," said Lucky Anighoro, Pharm.D., St. Michael's Medical Center, Newark, N.J. He noted that following ocular administration, nepafenac penetrates the cornea and is converted to amfenac, an NSAID. Amfenac is believed to exert its actions by inhibiting the enzyme prostaglandin H synthase (cyclooxygenase), which is required for prostaglandin production.
The approval of nepafenac was based on the results of two placebo-controlled studies involving over 680 patients. Nepafenac suspension was dosed three times daily, beginning one day prior to cataract surgery, continuing on the day of surgery, and for 14 days postoperatively. Approximately 80% of the patients receiving nepafenac therapy reported no ocular pain on the day following cataract surgery, compared with about one-half of the patients in the placebo group. Additionally, patients treated with nepafenac experienced less clinically significant inflammation than those in the placebo group.
"The package insert does not clearly state which adverse events during clinical trials were associated with nepafenac therapy rather than with the cataract surgery itself," stated Anighoro. "The product labeling identifies that commonly reported adverse events following cataract surgery included decreased visual acuity, capsular opacity, foreign body sensation, and increased ocular pressure." These events, he said, occurred in approximately 5% to 10% of patients.
According to its maker, nepafenac should be used with caution in individuals who have previously experienced sensitivities to other NSAIDs, acetylsalicylic acid, and phenylacetic acid derivatives. The package labeling advises that topical NSAIDs, including nepafenac, may delay healing, and the potential for healing problems may be increased with concomitant use of topical NSAIDs and topical corticosteroids.
The company urges caution with nepafenac therapy. Nepafenac, as with other NSAIDs, may increase bleeding time due to interference with platelet aggregation. Anighoro emphasized that patients who are receiving other medications that may prolong bleeding time, such as aspirin or warfarin, should be appropriately informed and monitored closely.
The recommended dose of nepafenac ophthalmic suspension is one drop in the affected eye(s) three times daily beginning one day prior to cataract surgery, continued on the day of surgery and through the first two weeks of the postoperative period. The manufacturer warns, however, that the continued use of NSAIDs to the eye may increase the risk for corneal problems.
The author is a writer and hospital pharmacist in New Jersey.