Proparacaine (Proxymetacaine)

Proparacaine, also called proxymetacaine, is a rapid-acting topical ophthalmic local anesthetic. It provides brief surface anesthesia, principally of the cornea, for examination and minor procedures. Veterinary use centers on short procedural interventions or temporary relief of surface pain sufficient to permit assessment and treatment.

Group

Topical ophthalmic local anaesthetic

Mechanism of Action

Proparacaine blocks voltage-gated sodium channels in superficial sensory nerve membranes. Reduced sodium influx prevents initiation and propagation of action potentials, temporarily interrupting transmission of corneal pain and touch signals. Limited local penetration concentrates the anesthetic effect at the ocular surface. Recovery follows redistribution and removal of active drug from the treated tissue.

Dose Rates

Dogs

Use / stage	Dose	Route	Schedule	Instructions
Diagnostic corneal anaesthesia	Reference only	TOPICAL	Once	One or two drops of 0.5% ophthalmic solution before examination or procedure.
Extended superficial procedure	Reference only	TOPICAL		One drop may be repeated every 5-10 minutes for 5-7 doses during a procedure; not a home-use analgesic course.

Cats

Use / stage	Dose	Route	Schedule	Instructions
Diagnostic corneal anaesthesia	Reference only	TOPICAL	Once	One or two drops of 0.5% ophthalmic solution before examination or procedure.
Extended superficial procedure	Reference only	TOPICAL		One drop may be repeated every 5-10 minutes for 5-7 doses during a procedure; not a home-use analgesic course.

Horses

Use / stage	Dose	Route	Schedule	Instructions
Diagnostic corneal anaesthesia	Reference only	TOPICAL	Once	One or two drops of 0.5% ophthalmic solution before examination or procedure.
Extended superficial procedure	Reference only	TOPICAL		One drop may be repeated every 5-10 minutes for 5-7 doses during a procedure; not a home-use analgesic course.

Indications

Topical ocular-surface anesthesia for tonometry, corneal examination or sampling in veterinary patients.
Brief corneal anesthesia for selected superficial foreign-body removal or other minor ophthalmic procedures.
Temporary relief of corneal surface pain to permit diagnostic examination or therapeutic intervention.

Contraindications

Do not dispense repeated topical anaesthetic as ongoing corneal-ulcer pain treatment.
Hypersensitivity to the preparation.

Interactions

Use sequential ocular drugs with care to avoid contamination and dilution of diagnostic samples.

Adverse effects

Transient stinging; repeated use can injure corneal epithelium and delay healing.

Toxicity

Stop repeated exposure and evaluate corneal damage; support the ocular surface.

Preparations

Preparation	Form	Strength	Route
Proparacaine hydrochloride ophthalmic solution 0.5% Also called proxymetacaine hydrochloride; ophthalmic use only.	Other	5 mg / mL	TOPICAL

Monitoring and Administration

Typical corneal anaesthesia lasts 5-10 minutes. Protect the anaesthetised eye from rubbing or trauma.

Protect from light; some preparations require refrigeration. Follow the specific product, not a universal storage rule.