Proxymetacaine
Proxymetacaine hydrochloride
Also known as: Alcaine · Minims Proxymetacaine · Ophthaine · Proxymetacaine hydrochloride · Proparacaine hydrochloride
Reviewed by the VetSheet Veterinary TeamUpdated Apr 5, 2026Evidence-based veterinary reference
Doses are a clinical reference for licensed veterinary professionals. Always confirm against the current label and the individual patient.
Dosing by species
🌎 NA — North America🌍 EU — Europe
Dogs
| Indication | Dose | Route | Frequency | Duration | Region |
|---|---|---|---|---|---|
| Ocular surface anaesthesia | 1-2 drops/eye | topical | PRN | Single application (or serial for depth) | 🌍 EU |
| Aural/nasal anaesthesia | 5-10 drops/ear or nose | topical | q5-10min | Maximum 3 doses if used intranasally | 🌍 EU |
- Ocular surface anaesthesia: Maximal effect at 15 min, duration 45-55 min.
Cats
| Indication | Dose | Route | Frequency | Duration | Region |
|---|---|---|---|---|---|
| Ocular surface anaesthesia | 1-2 drops/eye | topical | PRN | Single application | 🌍 EU |
- Ocular surface anaesthesia: Maximal effect at 15 min, duration 25 min.
Doses are a clinical reference for licensed veterinary professionals. Always confirm against the current label and the individual patient.
Overview
Proxymetacaine (also known as proparacaine) is a rapid-acting topical local anaesthetic used primarily on the ocular surface (cornea and conjunctival sac), as well as the external auditory meatus and nares. It acts rapidly (within 1 minute) and provides anaesthesia for 25-55 minutes depending on the species.
Clinical Warning: All topical anaesthetics are toxic to the corneal epithelium. Repeated application delays the healing of ulcers and can lead to severe corneal melting. Never dispense for home use as a therapeutic analgesic.
Clinical Pearl: Serial application increases both the duration and depth of anaesthesia. Because topical anaesthetics block reflex tear production, they should not be applied prior to performing a Schirmer tear test.
Mechanism of action
Local anaesthetic action is dependent on the reversible blockade of voltage-gated sodium channels → prevents the influx of sodium ions → inhibits the propagation of an action potential along the nerve fibre.
Sensory nerve fibres are blocked before motor nerve fibres, allowing a selective sensory blockade at low doses.
Safety & warnings
Contraindications
- Therapeutic use (e.g., home pain management)
- Application prior to a Schirmer tear test
Adverse effects
- Conjunctival hyperaemia (common)
- Local irritation / chemosis (occasional)
- Corneal epithelial toxicity
- Delayed corneal ulcer healing
Precautions
Corneal Toxicity: Repeated use causes severe epithelial toxicity and delays ulcer healing. Must only be used for diagnostic or minor surgical procedures in a clinical setting. Diagnostic Interference: Do not use before a Schirmer tear test as it abolishes reflex tearing.
Monitoring
- Corneal integrity (fluorescein staining if damage is suspected)
- Resolution of anaesthesia (protect the eye from trauma while numb)
Pharmacokinetics
Absorption
Rapid onset (< 1 minute) following topical application to mucous membranes.
Distribution
Acts locally at the site of application (cornea, conjunctiva, nasal mucosa, ear canal).
Metabolism
Ester-type local anaesthetics are generally hydrolyzed by plasma pseudocholinesterases and esterases in the tissue.
Elimination
Metabolites are primarily excreted via the kidneys.
Overdose
Overdosage via repeated topical application leads to severe corneal toxicity, epithelial sloughing, delayed healing of ulcers, and potentially corneal melting. Systemic toxicity is rare with standard ophthalmic use but could theoretically cause CNS excitation followed by depression and cardiovascular collapse if massive amounts are absorbed through mucous membranes.
Available products
Formulations
- 0.5% ophthalmic solution (single-use vials)
Veterinary
- Proxymetacaine 0.5% single-use vials
Human-labeled
- Minims Proxymetacaine Hydrochloride 0.5% eye drops
- Alcaine 0.5% ophthalmic solution
Regulatory status
Commonly known as Proparacaine in the US.
POM (Prescription Only Medicine)
POM-V
No regulatory data for: 🇭🇰 HK · 🇹🇼 TW · 🇯🇵 JP · 🇰🇷 KR · 🇦🇺 AU
Storage & stability
Store in a refrigerator (2-8°C) and protect from light. Efficacy is reduced if stored at room temperature for >2 weeks.
Client information
This medication is for in-clinic veterinary use only to facilitate eye examinations or minor procedures.
Warning: It is never prescribed for home use. Repeated use of numbing eye drops will cause severe, potentially blinding damage to the surface of the eye (corneal ulcers). While your pet's eye is numb after the vet visit, prevent them from rubbing or scratching it.
VetSheet drug reference is intended for licensed veterinary professionals as a clinical decision-support aid, not a substitute for professional judgement or the manufacturer’s current label.