Procaine is a local anesthetic drug of the amino ester group. It is most commonly used in dental procedures to numb the area around a tooth and is also used to reduce the pain of intramuscular injection of penicillin. Procaine is typically supplied as procaine hydrochloride and acts by reversible blockade of voltage gated sodium channels in nerve membranes, preventing action potential propagation; it preferentially affects small myelinated sensory fibers and produces a rapid onset of anesthesia with a relatively short duration of clinical effect, commonly 30 to 60 minutes for infiltration doses. The compound is hydrolyzed in plasma by esterases to p-aminobenzoic acid and diethylaminoethanol, has a base pKa near 8.9 which influences onset and potency at physiological pH, and is formulated in concentrations from 0.5 to 2 percent with or without vasoconstrictors depending on the procedure. Clinical considerations include potential hypersensitivity reactions related to p-aminobenzoic acid derivatives, dose limits to avoid systemic toxicity, and stability considerations since ester linkages are susceptible to hydrolysis and oxidative degradation.
Parent: Procaine
Parent: Procaine Hydrochloride / Procaine
Pharmaceutical grade procaine hydrochloride is manufactured and tested with strict impurity limits and controlled related compound profiles to meet pharmacopeial quality standards. Typical quality control acceptance criteria used by manufacturers and testing laboratories aim for individual related substances to be at or below about 0.1 to 0.2 percent w by w and for total related substances to be below about 0.5 percent w by w, although specific limits may be defined by the applicable monograph or regulatory filing. Known related compounds and degradation products include p-aminobenzoic acid and its isomers, diethylaminoethanol, smaller ester hydrolysis products, oxidative impurities and trace amounts of residual solvents or reagents from synthesis; these are monitored by validated chromatographic methods. Residual solvents and elemental impurities are controlled to ICH Q3C and Q3D guideline limits respectively, and water content and assay are specified to ensure potency and reduce generation of hydrolytic impurities during storage.
Procaine is used primarily as a short acting local anesthetic for dental infiltration and nerve block procedures and historically to reduce the pain of intramuscular injections such as penicillin; it may also be used for minor skin and soft tissue procedures where a short duration anesthetic effect is appropriate.
Procaine has largely been supplanted by amide local anesthetics such as lidocaine and mepivacaine because those agents have faster onset at clinical pH, greater stability, longer duration options, and lower incidence of allergic reactions related to p-aminobenzoic acid metabolites; advances in formulation and safety monitoring have driven the shift away from ester type agents in many settings.
No, procaine is not a psychoactive recreational drug; it is a local anesthetic acting on peripheral nerves. At supra therapeutic or toxic systemic concentrations it can produce central nervous system effects such as dizziness, tinnitus, visual disturbances and in severe cases seizures, but these are toxic effects rather than psychoactive, mood altering effects sought in recreational use.
Common synonyms include novocaine and procaine hydrochloride; the chemical name is 2-(diethylamino)ethyl 4-aminobenzoate.
