Products
Procaine has been commercially available in many countries since 1941 in the form of ear drops (Otalgan). Currently, it is available in many countries only as a combination preparation.
Structure and properties
Procaine (C13H20N2O2, Mr = 236.31 g/mol) was synthesized as the first synthetic ester local anesthetic by Einhorn in 1905. The local anesthetic effect of cocaine, the first local anesthetic, had previously been discovered by Carl Koller in 1884 for operations on the eye. In pharmaceuticals, procaine is also present as procaine hydrochloride, a white crystalline powder that is very soluble in water.
Effect
Procaine (ATC C05AD05, ATC N01BA02, ATC S01HA05) has local anesthetic properties. It reversibly and locally inhibits the conduction of sensitive nerve fibers by blocking sodium channels in nerve cells and other excitable structures. Procaine is rapidly hdrolyzed by esterases.
Indication
Procaine is indicated for local anesthesia. It is used for inflammation and pain in the oral cavity, such as gingival pockets, aphthae, and pressure sores under dentures, or for therapy of pain in the ear, such as otitis externa, otitis media, irritation, and nonbacterial inflammation of the ear of various causes, such as after exercise (swimming, diving, flying) or in association with a cold.
Contraindications
- Hypersensitivity
- Pregnancy and lactation
- Ear drops with procaine should not be used in the presence of a perforated eardrum.
- The use of procaine in the mouth is contraindicated in children and adolescents.
For complete precautions, see the drug label.
Interactions
Concomitant use of vasoconstrictors may result in delayed clearance of procaine and prolongation of its duration of action. The effects of procaine may be potentiated by physostigmine and by nondepolarizing muscle relaxants. Procaine may decrease the effect of sulfonamides.
Adverse effects
Local allergic reactions may occur with the use of procaine. When administered systemically, adverse reactions affecting the central nervous system and cardiovascular system may occur. Procaine is not commercially available for systemic use in many countries, and relevant systemic absorption is unlikely when used in the mouth and ear with an intact eardrum.