Nepafenac is a nonsteroidal anti-inflammatory drug (NSAID) prodrug specifically formulated for ophthalmic use. It is a unique, highly lipophilic prodrug that rapidly penetrates the cornea, where it is converted by intraocular hydrolases to amfenac, its active metabolite. Amfenac is a potent inhibitor of cyclooxygenase (COX-1 and COX-2), thereby reducing the synthesis of prostaglandins, which are key mediators of ocular inflammation, pain, and miosis during cataract surgery. Its 0.3% w/v concentration is the standard therapeutic strength for postoperative management.
Adult: One drop (approximately 0.05 mL) instilled into the conjunctival sac of the affected eye(s) 3 times daily, beginning 1 day prior to cataract surgery, continued on the day of surgery, and for 2 weeks postoperatively. For pain and inflammation treatment only, use for 14 days.
Note: Wash hands before use. Tilt head back, pull lower eyelid down to form a pouch. Instill one drop. Close eyes gently for 1-2 minutes and apply gentle pressure to the nasolacrimal duct (inner corner of eye) for at least 1 minute to minimize systemic absorption. Do not touch dropper tip to any surface. If using other eye drops, wait at least 5 minutes between applications. Ophthalmic solutions are typically applied last after ointments.
Nepafenac is a prodrug designed for optimal ocular penetration. Once it traverses the corneal epithelium, it is rapidly converted by intraocular tissue hydrolases to amfenac. Amfenac is a potent, non-selective inhibitor of both cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2) enzymes. By inhibiting these enzymes, it blocks the conversion of arachidonic acid to prostaglandin precursors (PGH2). This reduction in prostaglandin synthesis (particularly PGE2) in the anterior segment of the eye (iris, ciliary body) mediates its therapeutic effects: reduction of inflammation, pain, and miosis.
Pregnancy: Category C. Animal reproduction studies have shown adverse effects (increased post-implantation loss). There are no adequate and well-controlled studies in pregnant women. Use during pregnancy only if the potential benefit justifies the potential risk to the fetus. Avoid use in late pregnancy due to risk of premature closure of ductus arteriosus (a class effect of NSAIDs).
Driving: May cause transient blurred vision immediately after instillation. Patients should not drive or use machinery until vision clears.
| Other Topical NSAIDs (e.g., Ketorolac, Bromfenac) | Increased risk of corneal side effects (melt, perforation). Avoid concomitant use. | Major |
| Topical Corticosteroids (e.g., Dexamethasone, Prednisolone) | May be used together for synergistic anti-inflammatory effect, but also may increase risk of elevated IOP and cataract formation with long-term use. | Moderate |
| Anticoagulants (e.g., Warfarin, Apixaban) | Theoretically may increase risk of ocular bleeding (hyphema) due to antiplatelet effect of NSAIDs, though systemic levels are low. Monitor. | Moderate |
| Topical Cholinergic Agents (e.g., Pilocarpine) | NSAIDs may attenuate the miotic effect of pilocarpine. | Minor |