Proparacaine is a potent, rapid-acting, ester-type topical ophthalmic anesthetic. It is a para-aminobenzoic acid (PABA) derivative, structurally related to tetracaine. It is used exclusively for surface anesthesia of the eye for diagnostic and minor surgical procedures. It is not indicated for prolonged use or self-medication.
Adult: For tonometry: 1-2 drops instilled into the conjunctival sac just prior to measurement. For foreign body removal or short procedures: 1-2 drops every 5-10 minutes for 1 to 3 doses as required.
Note: Wash hands. Tilt head back, pull down lower eyelid to form a pouch. Instill the prescribed number of drops. Avoid touching the dropper tip to the eye, eyelids, or any surface. Close eyes gently for 1-2 minutes. Apply gentle pressure to the lacrimal sac (inner corner of eye) for about 1 minute to minimize systemic absorption. Do not blink excessively.
Proparacaine reversibly blocks the generation and conduction of nerve impulses by decreasing the permeability of neuronal membranes to sodium ions. This inhibition of sodium influx during depolarization prevents the initiation and propagation of action potentials, resulting in a reversible loss of sensation (anesthesia) in the corneal and conjunctival tissues.
Pregnancy: Category C: Animal reproduction studies have not been conducted. It is not known whether proparacaine can cause fetal harm when administered to a pregnant woman. Use only if clearly needed and the potential benefit justifies the potential risk to the fetus. Minimal systemic absorption makes risk low.
Driving: Patients should be warned that temporary blurring of vision or stinging may occur after instillation. They should not drive or operate hazardous machinery until their vision is completely clear, which is usually within 15-30 minutes.
| Sulfonamides (e.g., Sulfacetamide eye drops) | The metabolite PABA may antagonize the antibacterial effect of sulfonamides. | Moderate |
| Cholinesterase inhibitors (e.g., Echothiophate iodide eye drops) | Theoretically may reduce the metabolism of proparacaine, potentially increasing its duration and toxicity. Clinical significance is unclear. | Low |
Same composition (Proparacaine (NA)), different brands: