NOVOCAIN
Clinical safety rating: caution
Comprehensive clinical and safety monograph for NOVOCAIN (NOVOCAIN).
Procaine, an ester-type local anesthetic, reversibly binds to the intracellular portion of voltage-gated sodium channels, inhibiting sodium influx and blocking nerve impulse conduction.
| Metabolism | Primarily hydrolyzed by plasma pseudocholinesterase (butyrylcholinesterase) to para-aminobenzoic acid (PABA) and diethylaminoethanol; hepatic metabolism minor. |
| Excretion | Renal excretion of para-aminobenzoic acid (PABA) and diethylaminoethanol as major metabolites; <2% excreted unchanged in urine. Biliary/fecal: minimal. |
| Half-life | Plasma half-life: approximately 30–60 seconds due to rapid hydrolysis by pseudocholinesterases; clinical effects short-lived. |
| Protein binding | Approximately 85% bound to plasma proteins (primarily alpha-1-acid glycoprotein and albumin). |
| Volume of Distribution | Vd: approximately 0.7–1.0 L/kg; reflects distribution into total body water with rapid tissue uptake. |
| Bioavailability | Oral: negligible due to extensive first-pass hydrolysis; Parenteral (IV/SC/IM): 100% for local anesthesia. |
| Onset of Action | Infiltration: 2–5 min; Nerve block: 5–15 min; Topical: not effective due to poor mucosal penetration. |
| Duration of Action | Infiltration: 30–60 min; Nerve block: 45–90 min; duration prolonged with epinephrine (up to 2 hours). |
Local infiltration: 0.5% solution, up to 20 mL (100 mg) per dose; nerve block: 1-2% solution, 5-10 mL (50-200 mg); maximum single dose: 7 mg/kg or 350 mg (without epinephrine).
| Dosage form | INJECTABLE |
| Renal impairment | No specific guidelines; use with caution in severe renal impairment (GFR <30 mL/min) due to risk of metabolic acidosis from procaine metabolism. |
| Liver impairment | Child-Pugh A: no adjustment; Child-Pugh B: reduce dose by 50%; Child-Pugh C: contraindicated. |
| Pediatric use | Local infiltration: 0.5% solution, 2.5-5 mg/kg (max 100 mg); nerve block: 1% solution, 2.5-5 mg/kg; maximum single dose: 5 mg/kg. |
| Geriatric use | Reduce maximum single dose to 5 mg/kg (max 250 mg); monitor for hypotension and CNS excitation; dose intervals at least 2 hours. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for NOVOCAIN (NOVOCAIN).
| Breastfeeding | Procaine is excreted into breast milk in small amounts; M/P ratio unknown. The American Academy of Pediatrics considers it compatible with breastfeeding. Use with caution, monitor infant for signs of CNS effects. |
| Teratogenic Risk | Procaine (Novocain) is a pregnancy category C drug. Animal reproduction studies have not been conducted. Inadvertent intravascular administration may cause fetal bradycardia and acidosis. Use in first trimester only if clearly needed; potential for placental transfer. Avoid in third trimester near term due to risk of neonatal CNS depression. |
■ FDA Black Box Warning
Not available.
| Serious Effects |
["Hypersensitivity to procaine or other ester-type local anesthetics","Hypersensitivity to PABA or parabens","Severe bleeding disorders or infection at injection site","Myasthenia gravis (relative caution)","Treatment with cholinesterase inhibitors (relative caution)"]
| Precautions | ["Risk of methemoglobinemia, especially with high doses or in patients with G6PD deficiency","Cardiovascular effects: hypotension, arrhythmias, cardiac arrest","CNS toxicity: restlessness, seizures, respiratory depression","Allergic reactions to ester anesthetics (cross-sensitivity with PABA)"] |
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| Fetal Monitoring |
| Monitor maternal blood pressure, heart rate, and ECG during administration. Fetal heart rate monitoring recommended if used during pregnancy. Assess for signs of local anesthetic systemic toxicity (LAST) including CNS and cardiovascular effects. |
| Fertility Effects | No specific studies available. No evidence of significant impact on fertility. As an ester local anesthetic, no known hormonal effects. |