Nepafenac

Nepafenac
Nepafenac-2D-skeletal.svg
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Nepafenac is a non-steroidal anti-inflammatory drug (NSAID) used in ophthalmology to manage pain and inflammation associated with cataract surgery. It is a prodrug that is converted to amfenac in the eye, which then exerts its therapeutic effects.

Mechanism of Action

Nepafenac is a prodrug that, upon instillation into the eye, is rapidly converted by intraocular hydrolases to its active form, amfenac. Amfenac inhibits the activity of cyclooxygenase (COX-1 and COX-2) enzymes, which are responsible for the conversion of arachidonic acid to prostaglandins. Prostaglandins are mediators of inflammation and pain, and their inhibition leads to reduced inflammation and analgesia.

Clinical Use

Nepafenac is primarily indicated for the treatment of pain and inflammation associated with cataract surgery. It is administered as an ophthalmic suspension and is typically used in the perioperative period to manage postoperative inflammation and reduce the risk of cystoid macular edema.

Dosage and Administration

Nepafenac is available as a 0.1% ophthalmic suspension. The recommended dosage is one drop applied to the affected eye(s) three times daily, beginning one day prior to cataract surgery, and continued on the day of surgery and through the first two weeks of the postoperative period.

Side Effects

Common side effects of nepafenac include eye pain, ocular irritation, and conjunctival hyperemia. Less common but more serious side effects can include corneal thinning, corneal erosion, and delayed healing. Patients should be monitored for signs of corneal complications, especially if they are using other topical ophthalmic medications.

Contraindications and Precautions

Nepafenac is contraindicated in patients with known hypersensitivity to nepafenac, amfenac, or any other components of the formulation. Caution is advised in patients with a history of herpetic keratitis or other corneal conditions. It should be used with caution in patients with bleeding tendencies or those on anticoagulant therapy, as NSAIDs can increase the risk of bleeding.

Pharmacokinetics

After topical ocular administration, nepafenac is rapidly absorbed and converted to amfenac in the eye. The systemic exposure to nepafenac and amfenac is low, minimizing the risk of systemic side effects. The elimination half-life of amfenac in the aqueous humor is approximately 1.7 hours.

Related Pages

• Non-steroidal anti-inflammatory drug
• Cataract surgery
• Prodrug
• Cyclooxygenase