What is procaine injection used to treat?

October 8, 2025 •

3 min read

First synthesized in 1905, procaine, formerly known by the brand name Novocain, was developed as a safer anesthetic alternative to cocaine. While its primary use has shifted due to modern alternatives, a procaine injection is still used to treat a variety of conditions, from bacterial infections (in combination with penicillin) to providing local anesthesia.

Quick Summary

A procaine injection is used for localized pain relief (local anesthesia) and as part of a medication to treat certain bacterial infections. It has largely been replaced by newer drugs for routine use but maintains niche applications in medicine and is still common in veterinary care.

Key Points

Used for Local Anesthesia: Procaine is a local anesthetic used to numb small areas of the body for dental work and minor surgical procedures.
Extends Penicillin's Effects: It is most commonly used today in combination with penicillin G (as procaine penicillin G) to prolong the antibiotic's action against specific bacterial infections.
Older and Shorter-Acting: As an older anesthetic, it has a slower onset and shorter duration than modern alternatives like lidocaine.
Used in Integrative Therapies: Some integrative medicine and pain clinics use procaine infusions or injections in neural therapy to address chronic pain, inflammation, and nervous system balance.
Acts by Blocking Nerve Signals: The mechanism of action involves blocking voltage-gated sodium channels in nerve membranes to prevent the transmission of pain signals.
Requires Medical Supervision: The injection should only be administered by a qualified healthcare provider due to the risk of allergic reactions and other serious side effects, especially with high doses or in sensitive individuals.

Primary Uses of Procaine Injection

Procaine hydrochloride is an ester-type local anesthetic with a history spanning over a century. While newer, more potent, and longer-acting local anesthetics like lidocaine have replaced it in many routine procedures, procaine retains a role in specific therapeutic applications. Its uses can be categorized based on how it is administered and combined with other substances.

Local and Regional Anesthesia

Procaine was historically used for localized pain relief in medical and dental settings. Administered by injection, it temporarily numbs areas by blocking nerve impulses. Its applications have included dental work, minor surgical procedures, nerve blocks, and historically, spinal and epidural anesthesia, although newer agents are now preferred for neuraxial blocks.

Procaine Penicillin G Combination

A significant current use of procaine is in combination with penicillin G. The procaine delays the absorption of the penicillin, providing a sustained antibiotic effect. This combination is used to treat specific moderate to severe bacterial infections, including certain streptococcal infections, syphilis caused by Treponema pallidum, pneumococcal pneumonia, scarlet fever, and erysipelas.

Alternative and Integrative Medicine

In some integrative medicine practices, procaine is used for its potential anti-inflammatory and regenerative effects. This includes Neural therapy, where procaine is injected into specific points to manage chronic pain, and diluted intravenous infusions for nervous system balance and improved circulation.

Veterinary Medicine

Procaine is also utilized in veterinary medicine for infiltration and nerve block anesthesia in animals, known for its short duration. It is frequently combined with penicillin G for veterinary use, similar to its application in humans.

Procaine vs. Modern Anesthetics: A Comparison

Modern anesthetics like lidocaine have largely supplanted procaine for many uses due to their superior properties. Here is a comparison of procaine and lidocaine in the context of local anesthesia.


Feature	Procaine (Novocain)	Lidocaine (Xylocaine)
Classification	Amino-ester	Amino-amide
Onset of Action	Slow	Prompt
Duration of Action	Short-acting (~30–60 mins)	Intermediate-acting, longer than procaine
Potency	Low	Intermediate
Side Effects	Allergic reactions (especially to PABA metabolite), lower incidence of TNS with spinal use	Higher incidence of transient neurological symptoms (TNS) with spinal use
Use with Vasoconstrictors	Often combined with epinephrine to prolong effects	Also combined with epinephrine to prolong effects
Metabolism	Hydrolyzed by plasma butyrylcholinesterase	Metabolized in the liver

Mechanism of Action and Side Effects

How Procaine Works

Procaine inhibits nerve impulse transmission by blocking voltage-gated sodium channels in nerve cell membranes. This prevents the influx of sodium ions, stopping the generation and propagation of action potentials and blocking pain signals. As an amino-ester anesthetic, it is metabolized in the plasma by pseudocholinesterase into para-aminobenzoic acid (PABA).

Potential Side Effects

Though generally safe, procaine can cause side effects related to high plasma levels, hypersensitivity, or altered sensitivity. Common effects include numbness, tingling, and minor reactions at the injection site. Rare but serious side effects can involve allergic reactions (difficulty breathing, swelling, hives), cardiovascular issues (chest pain, irregular heartbeat, low blood pressure), and central nervous system effects (anxiety, dizziness, seizures).

Who Should Avoid Procaine Injections?

Procaine is not suitable for everyone. Individuals with known allergies to procaine, other ester anesthetics, or PABA should avoid it. Caution is advised for those with asthma or sulfite sensitivity, and patients with heart conditions. Intravenous procaine is contraindicated in patients with myasthenia gravis. Interactions with medications like MAOIs, tricyclic antidepressants, and ergot drugs also require caution, especially when epinephrine is used.

Conclusion

While largely replaced for routine anesthesia, procaine injection, known historically as Novocain, remains relevant. Its primary modern use is in combination with penicillin G to prolong the antibiotic's effect for treating specific bacterial infections. It also has specialized applications in integrative medicine and veterinary care. However, its slower onset and shorter duration compared to agents like lidocaine limit its use for routine local anesthesia. Patients should consult a healthcare provider to determine if procaine is the appropriate and safest treatment for their needs.

For more detailed prescribing information, consult authoritative sources such as the National Institutes of Health.

Frequently Asked Questions

Yes, Novocain is the original brand name for the generic drug procaine. While Novocain was a common term for dental anesthesia, modern dentists primarily use newer, more effective local anesthetics like lidocaine.

Procaine penicillin G is a combination of procaine and the antibiotic penicillin. It is used to treat moderately severe bacterial infections, such as streptococcal infections, pneumococcal pneumonia, and syphilis.

Procaine is a vasodilator, meaning it widens blood vessels. To prolong its anesthetic effect, it is often combined with epinephrine, a vasoconstrictor, which narrows blood vessels at the injection site. This keeps the drug in the area longer and reduces systemic absorption.

Common side effects include mild, temporary numbness, tingling, pain, or swelling at the injection site. More severe reactions, such as allergic responses or cardiovascular effects, are rare.

While it was historically the primary dental anesthetic, procaine's slower onset and shorter duration have led to its replacement by more modern and efficient alternatives, such as lidocaine, for most routine dental work.

Lidocaine is generally more potent, acts faster, and lasts longer than procaine. A key difference in spinal anesthesia is that procaine has a lower risk of transient neurological symptoms (TNS) than lidocaine.

Yes, allergic reactions to procaine, especially to its metabolite PABA, can occur, though they are rare. Symptoms can range from hives and itching to more severe issues like anaphylaxis, requiring immediate medical attention.