Monofree (Oxybuprocaine Hydrochloride)

Monofree, an ophthalmic local anesthetic, is used to numb the ocular surface for various eye care procedures.

• Diagnostic eye procedures: provides temporary surface anesthesia to allow painless examination and testing.
• Minor ocular surgery: enables painless manipulation of ocular tissues during procedures such as foreign body removal.
• Laser eye treatments: supplies adequate anesthesia for laser photocoagulation or refractive procedures.

• Oxybuprocaine hydrochloride acts by reversibly blocking voltage‑gated sodium channels in peripheral nerve membranes of the corneal and conjunctival epithelium. This inhibition prevents the initiation and propagation of nerve impulses, resulting in loss of sensation on the ocular surface while preserving vascular and muscular function. The effect is rapid in onset and wears off as the drug is metabolized by ocular esterases.

Oxybuprocaine hydrochloride may cause ocular and systemic reactions, most of which are mild and transient.

Common Side Effects

• Stinging or burning sensation upon instillation.
• Transient blurred vision.
• Conjunctival hyperemia (redness).
• Excessive tearing.
• Mild allergic conjunctivitis.

Serious or Rare Side Effects

• Corneal epithelial toxicity or ulceration.
• Severe allergic reaction (anaphylaxis).
• Persistent corneal edema.
• Intraocular inflammation.
• Vision loss.

When using Monofree, consider the following precautions to ensure safe and effective application.

• Allergy assessment: verify no known hypersensitivity to ester‑type ocular anesthetics.
• Corneal disease: avoid in patients with active keratitis, epithelial defects or severe dry eye.
• Duration of use: limit application to the shortest time necessary; avoid repeated dosing.
• Professional supervision: administer only under the guidance of qualified eye‑care personnel.
• Systemic absorption: monitor infants and patients with compromised ocular barriers for systemic effects.
• Store at room temperature: keep in original container, protect from light and moisture.

Oxybuprocaine hydrochloride can interact with other ophthalmic agents; awareness of these interactions helps prevent adverse outcomes.

Major Interactions (Avoid)

• Concurrent use with other topical ocular anesthetics: may increase risk of corneal toxicity.
• Use with contact lenses during treatment: can trap the drug and enhance epithelial damage.
• Simultaneous administration of systemic sodium channel blockers: may potentiate anesthetic effect.

Moderate Interactions (Monitor Closely)

• Anticholinergic eye drops (e.g., atropine): may alter drug absorption.
• Beta‑blocker ophthalmic solutions: monitor intra‑ocular pressure changes.
• Topical anti‑inflammatory agents: assess for additive irritation.
• Systemic local anesthetics: observe for cumulative neurotoxic effects.