Proxymetacaine

Clinical pharmacology

Proxymetacaine is a local anesthetic which on topical application penetrates sensory nerve endings in the corneal tissue.

Mechanism of action

Proxymetacaine is believed to act as an antagonist on voltage-gated sodium channels to affect the permeability of neuronal membranes; how this inhibits pain sensations and the exact mechanism of action of proxymetacaine are, however, unknown.

Indications and usage

Proxymetacaine hydrochloride ophthalmic solution (eye drops) is indicated for procedures such as tonometry, gonioscopy, removal of foreign bodies, or other similar procedures requiring topical anesthesia of the cornea and conjunctiva.

Warnings

Proxymetacaine is for topical ophthalmic use only, and it is specifically not intended for injection. Prolonged use of this or any other topical ocular anesthetic may produce permanent corneal opacification with accompanying visual loss.

How supplied

Proxymetacaine is available as its hydrochloride salt in ophthalmic solutions at a concentration of 0.5%. Although it is no longer on patent, it is still marketed under the trade names Alcaine, Ak-Taine, and others. Proparacaine 0.5% is marketed as Poencaina by Poen Laboratories.

References

References

1. Anvisa. (2023-03-31). "RDC Nº 784 - Listas de Substâncias Entorpecentes, Psicotrópicas, Precursoras e Outras sob Controle Especial". [[Diário Oficial da União]].
2. (1984). "Efficacy of topical anaesthetics". Ophthalmic Research.
3. (1980). "The Pharmacological Basis of Therapeutics". MacMillan Pub..
4. (April 2009). "Prolonged corneal anaesthesia by proxymetacaine hydrochloride detected by a thermal cooling stimulus". Contact Lens & Anterior Eye.
5. "Poen-Caina generic. Price of poen-caina. Uses, Indications and Description".