Novokain

Novokain, commonly known as procaine, is an ester-type local anesthetic used to produce local infiltration and nerve block anesthesia. It is supplied as a salt, typically procaine hydrochloride, and may be combined with a vasoconstrictor such as epinephrine to prolong its effect. The name Novocain is a historic brand widely associated with this compound.

Procaine works by reversibly blocking voltage-gated sodium channels in nerve membranes, preventing initiation and propagation of action potentials. After administration, onset is usually within 5 to 15 minutes for infiltration anesthesia and longer for nerve blocks, with a typical duration of about 30 to 60 minutes, extended if a vasoconstrictor is used. It is commonly prepared in concentrations around 1% to 2% for superficial procedures.

Administration is common in dental and minor surgical settings for infiltration and regional blocks. Practitioners often employ aspiration before injection to reduce the risk of intravascular administration. Systemic toxicity can occur if injected into a blood vessel or given in excessive amounts, manifesting as central nervous system or cardiovascular symptoms.

Pharmacologically, procaine is rapidly hydrolyzed in plasma by esterases to para-aminobenzoic acid (PABA) and diethylaminoethanol. PABA can contribute to allergic reactions in susceptible individuals; as a result, ester-type anesthetics have a higher reported rate of hypersensitivity compared with many modern amide anesthetics.

Historically, procaine was introduced in 1905 by Alfred Einhorn, and the Novocain brand became widely used in the early 20th century. Today, procaine has largely been superseded by amide local anesthetics such as lidocaine, which offer longer-lasting effects, greater stability, and often a lower risk of allergic reactions in routine practice.