Proparacaine (Monograph)

Drug class: Local Anesthetics
VA class: OP700
CAS number: 5875-06-9

Medically reviewed by Drugs.com on Dec 22, 2023. Written by ASHP.

Introduction

Proparacaine hydrochloride is a short-acting local anesthetic with a rapid onset of action.

Uses for Proparacaine

Proparacaine is used for producing local anesthesia in tonometry, gonioscopy, removal of foreign bodies and sutures from the cornea, conjunctival scraping for diagnosis, and short operative procedures involving the cornea and conjunctiva; the combination preparation containing fluorescein sodium and proparacaine may be used for these indications when a disclosing agent is needed. Proparacaine may also be used as a surface anesthetic prior to the injection of procaine for intraocular or orbital surgery. Proparacaine may be used alone in cataract extractions and glaucoma surgery, but frequent instillations must be employed prior to surgery to increase the depth and prolong the duration of anesthesia.

Proparacaine Dosage and Administration

Administration

Proparacaine hydrochloride is applied topically to the eye in the form of a 0.5% solution.

Dosage

For tonometry, 1 or 2 drops of 0.5% proparacaine hydrochloride solution instilled immediately before measurement is usually sufficient. For the removal of foreign bodies or sutures from the eye, 1 or 2 drops may be instilled 2 or 3 minutes prior to beginning the procedure or every 5–10 minutes for 1–3 doses. When deeper, more prolonged anesthesia is required, as in cataract extraction or glaucoma surgery, 1 or 2 drops is instilled every 5–10 minutes for 5–7 doses.

Cautions for Proparacaine

Adverse Effects

Instillation of proparacaine in the eye at recommended concentration and dosage produces little or no initial irritation, stinging, or burning, and no visible hyperemia, lacrimation, increased winking, or change in pupil size; however, some local irritation and stinging may occur several hours after instillation of the drug. Proparacaine hydrochloride appears to be safe for use in patients sensitive to other local anesthetics, but local or systemic sensitivity occasionally occurs. Rarely, a severe, immediate-type, apparently hyperallergic corneal reaction may occur. The reaction is manifested by acute, intense, and diffuse epithelial keratitis; a gray, ground-glass appearance; sloughing of large areas of necrotic epithelium; corneal filaments and, sometimes, iritis with descemetitis. Allergic contact dermatitis with drying and fissuring of the fingertips has also been reported. Softening and erosion of the corneal epithelium and conjunctival congestion and hemorrhage have occurred.

Precautions and Contraindications

Proparacaine hydrochloride ophthalmic solution should be used with caution and sparingly in patients with known allergies, cardiac disease, or hyperthyroidism. The long-term toxicity of proparacaine is not known; prolonged use may possibly delay wound healing. Prolonged use of a topical ocular anesthetic is not recommended, since corneal opacification with accompanying loss of vision may occur. Although extremely rare following ophthalmic administration of local anesthetics, it should be kept in mind that systemic toxicity, manifested by CNS stimulation followed by depression, may occur. Patients should be warned not to touch or rub the eye(s) until the anesthesia has worn off.

Proparacaine hydrochloride ophthalmic solution is contraindicated in patients with known hypersensitivity to the drug or any ingredients in the formulations.

Pharmacology

Topical application of a 0.5% solution of proparacaine hydrochloride or tetracaine hydrochloride to the eye produces similar local anesthetic effects. Instillation of a 0.5% solution of proparacaine hydrochloride in the eye produces local anesthesia within 20 seconds. The duration of action is up to 15 minutes or longer.

Chemistry and Stability

Chemistry

Proparacaine hydrochloride is a short-acting local anesthetic of the ester type with a rapid onset of action. Proparacaine is structurally similar to other local anesthetics of the ester type, but its amino group is in meta position to the benzoate chain rather than in para position; this may explain the lack of cross-sensitization between proparacaine and other local anesthetics.

Proparacaine hydrochloride occurs as a white to off-white, or faintly buff-colored, odorless, crystalline powder. The drug is soluble in water and in warm alcohol. Proparacaine hydrochloride ophthalmic solution is a sterile, aqueous solution of the drug. The solution is colorless or faintly yellow and has a pH of 4–6; pH may be adjusted during manufacture of the solution with hydrochloric acid and/or sodium hydroxide. Proparacaine hydrochloride ophthalmic solution may also contain benzalkonium chloride and/or chlorobutanol as preservatives and glycerin.

Stability

Proparacaine hydrochloride ophthalmic solution should be stored in tight, light-resistant containers and refrigerated at 2–8°C to retard discoloration of the solution. Discolored solutions of proparacaine hydrochloride should not be used.

Preparations

Excipients in commercially available drug preparations may have clinically important effects in some individuals; consult specific product labeling for details.

Please refer to the ASHP Drug Shortages Resource Center for information on shortages of one or more of these preparations.

* available from one or more manufacturer, distributor, and/or repackager by generic (nonproprietary) name

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