Proxymetacaine (

INN Inns are generally establishments or buildings where travelers can seek lodging, and usually, food and drink. Inns are typically located in the country or along a highway; before the advent of motorized transportation they also provided accommo ...

) or proparacaine (

USAN 280px, "Samguk Sagi" Book 04. Silla's Records. In 512, Usan-guk（于山國）was Ulleungdo（鬱陵島） Usan-guk, or the State of Usan, occupied Ulleung-do and the adjacent islands during the Korean Three Kingdoms period. According to th ...

) is a

topical anesthetic A topical anesthetic is a local anesthetic that is used to numb the surface of a body part. They can be used to numb any area of the skin as well as the front of the eyeball, the inside of the nose, ear or throat, the anus and the genital area. To ...

drug of the aminoester group.

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 channel Sodium channels are integral membrane proteins that form ion channels, conducting sodium ions (Na+) through a cell's membrane. They belong to the superfamily of cation channels and can be classified according to the trigger that opens the chann ...

s 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 drop Eye drops or eyedrops are liquid drops applied directly to the surface of the eye usually in small amounts such as a single drop or a few drops. Eye drops usually contain saline to match the salinity of the eye. Drops containing only saline ...

s) is indicated for procedures such as

tonometry Tonometry is the procedure eye care professionals perform to determine the intraocular pressure (IOP), the fluid pressure inside the eye. It is an important test in the evaluation of patients at risk from glaucoma. Most tonometers are calibrated ...

gonioscopy Gonioscopy a routine ophthalmological procedure that measures the angle between the iris and the cornea (the iridocorneal angle), using a goniolens (also known as a gonioscope) together with a slit lamp or operating microscope. Its use is import ...

, removal of

foreign bodies A foreign body (FB) is any object originating outside the body of an organism. In machinery, it can mean any unwanted intruding object. Most references to foreign bodies involve propulsion through natural orifices into hollow organs. Foreign bo ...

, or other similar procedures requiring topical anesthesia of the

cornea The cornea is the transparent front part of the eye that covers the iris, pupil, and anterior chamber. Along with the anterior chamber and lens, the cornea refracts light, accounting for approximately two-thirds of the eye's total optical ...

and

conjunctiva The conjunctiva is a thin mucous membrane that lines the inside of the eyelids and covers the sclera (the white of the eye). It is composed of non-keratinized, stratified squamous epithelium with goblet cells, stratified columnar epithelium ...

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 The human cornea is a transparent membrane which allows light to pass through it. The word corneal opacification literally means loss of normal transparency of cornea. The term corneal opacity is used particularly for the loss of transparency of c ...

with accompanying

visual loss Visual impairment, also known as vision impairment, is a medical definition primarily measured based on an individual's better eye visual acuity; in the absence of treatment such as correctable eyewear, assistive devices, and medical treatment� ...

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 name A trade name, trading name, or business name, is a pseudonym used by companies that do not operate under their registered company name. The term for this type of alternative name is a "fictitious" business name. Registering the fictitious name w ...

s Alcaine, Ak-Taine, and others. Proparacaine 0.5% is marketed as Poencaina by Poen Laboratories.

References

{{Local anesthetics Local anesthetics Benzoate esters Anilines Novartis brands Phenol ethers Diethylamino compounds