P-caine

• Topical anesthesia of the eye:
  Used to induce surface anesthesia for ophthalmic procedures including tonometry, gonioscopy, removal of foreign bodies, cataract surgery, and other minor ocular surgeries.
• Diagnostic procedures:
  To facilitate painless examination of the cornea and conjunctiva.

• Route: Ophthalmic (eye drops).
• Adult and Pediatric: Instill 1 to 2 drops into the affected eye’s conjunctival sac approximately 1 to 3 minutes before the procedure.
• Frequency: May repeat every 5 to 10 minutes during prolonged procedures, but total exposure should be limited to prevent corneal toxicity.
• Special populations: Use with caution in patients with ocular surface damage or dry eye disease.
• Note: Not intended for continuous or long-term use.

Proparacaine hydrochloride is a local anesthetic that blocks voltage-gated sodium channels on neuronal membranes of the corneal and conjunctival nerves. This blockade inhibits the initiation and propagation of action potentials, resulting in reversible loss of sensation in the ocular surface tissues. The anesthetic effect facilitates painless ophthalmic procedures by numbing the cornea and conjunctiva rapidly and temporarily.

• Absorption: Minimal systemic absorption after topical ocular administration.
• Onset: Rapid, within 15 to 30 seconds.
• Duration: Approximately 10 to 20 minutes per dose.
• Metabolism: Hydrolyzed by plasma and ocular tissue esterases to inactive metabolites.
• Excretion: Metabolites eliminated primarily via renal excretion.

• Pregnancy: FDA Category C. Use only if the potential benefit justifies the potential risk to the fetus; limited data on safety in pregnant women.
• Lactation: Unknown if excreted in human milk; caution advised. Minimal systemic absorption suggests low risk.

• Local anesthetic, ophthalmic.
• Ester-type topical anesthetic.

• Known hypersensitivity to proparacaine hydrochloride or other ester anesthetics.
• Use contraindicated in patients with corneal epithelial defects or severe ocular surface disease unless closely monitored.

• Excessive or prolonged use can cause corneal epithelial toxicity, keratitis, or corneal ulceration.
• Not recommended for self-administration or home use.
• Use cautiously in patients with pre-existing ocular surface disorders.
• Monitor for allergic reactions or local irritation.
• Avoid use if hypersensitivity reaction occurs.

• Common: Transient burning or stinging on instillation, blurred vision.
• Serious (rare): Corneal epithelial damage, allergic conjunctivitis, keratitis, corneal ulceration.
• Effects are typically dose-dependent and related to duration of exposure.

• No clinically significant systemic drug interactions due to minimal systemic absorption.
• Concomitant topical ocular agents may increase local irritation.

• Current ophthalmic guidelines recommend limiting use to short procedures due to risk of corneal toxicity with repeated dosing.
• Recent advisories emphasize avoiding self-administration and educating patients on risks of prolonged use.

• Store at controlled room temperature between 20°C and 25°C (68°F to 77°F).
• Protect from light and freezing.
• Keep container tightly closed when not in use.
• Discard unused solution as per manufacturer recommendations to ensure sterility.