Overview
Procaine is a local anesthetic of the ester type used primarily for infiltration anesthesia, nerve blocks, and spinal anesthesia. It has a rapid onset but short duration of action. It is also used diagnostically and therapeutically in some conditions due to its vasodilatory effects.
Mechanism of Action
Procaine blocks nerve impulse conduction by inhibiting sodium ion influx through voltage-gated sodium channels in neuronal cell membranes, preventing depolarization and action potential propagation.
Indications
- Local anesthesia for minor surgical procedures
- Infiltration anesthesia
- Peripheral nerve blocks
- Spinal anesthesia (limited use)
- Diagnostic/therapeutic use in some pain syndromes
Dosage
Dosage varies by route and procedure. Typical infiltration: 0.25-0.5% solution. Maximum single dose: 1000 mg. Always follow specific product labeling and clinical guidelines.
Contraindications
- Hypersensitivity to procaine or other ester-type anesthetics
- Severe shock or heart block
- Injection into infected or inflamed areas
- Myasthenia gravis (relative contraindication)
Side Effects
- CNS: dizziness, restlessness, tremors, convulsions
- Cardiovascular: hypotension, bradycardia, arrhythmias
- Allergic: urticaria, anaphylaxis
- Local: pain at injection site, tissue irritation
Interactions
- Sulfonamides: Procaine may inhibit antibacterial action
- MAO inhibitors: Increased risk of hypotension
- Other local anesthetics: Additive toxicity
- Succinylcholine: Prolonged neuromuscular blockade