NESACAINE
Clinical safety rating: caution
Comprehensive clinical and safety monograph for NESACAINE (NESACAINE).
Nesacaine (chloroprocaine) is an ester-type local anesthetic that blocks voltage-gated sodium channels in neuronal membranes, inhibiting the initiation and conduction of nerve impulses.
| Metabolism | Hydrolyzed in plasma by pseudocholinesterase (butyrylcholinesterase) to metabolites: 2-chloro-4-aminobenzoic acid and diethylaminoethanol. |
| Excretion | Renal: 90-95% as unchanged drug and metabolites (predominantly 4-hydroxypropycaine); biliary/fecal: <5% |
| Half-life | Terminal half-life: 40-60 minutes (rapidly metabolized by plasma pseudocholinesterase); clinical context: prolonged with hepatic dysfunction or atypical pseudocholinesterase |
| Protein binding | ~55% bound to alpha-1-acid glycoprotein and albumin |
| Volume of Distribution | Vd: 0.6-1.0 L/kg (distributes primarily into highly perfused tissues; low Vd due to rapid hydrolysis) |
| Bioavailability | Intravenous: 100%; epidural: >95%; infiltration: near 100% (localized); oral: negligible due to first-pass metabolism |
| Onset of Action | Infiltration: 2-5 minutes; Epidural: 5-10 minutes; Peripheral nerve block: 10-15 minutes |
| Duration of Action | Infiltration: 45-90 minutes (without epinephrine); with epinephrine: 60-120 minutes; epidural: 60-90 minutes |
Injectable local anesthetic: 1% or 2% solution, maximum dose 7 mg/kg (not to exceed 500 mg) with epinephrine, 4.5 mg/kg (not to exceed 300 mg) without epinephrine. Administer by infiltration or nerve block; may repeat at 30-minute intervals.
| Dosage form | INJECTABLE |
| Renal impairment | No specific dose adjustment required for renal impairment; caution with severe dysfunction due to potential accumulation of metabolites. |
| Liver impairment | Child-Pugh Class A: no adjustment; Child-Pugh Class B: reduce dose by 50%; Child-Pugh Class C: avoid use or use with extreme caution, maximum dose 50% of normal. |
| Pediatric use | Weight-based: 2-7 mg/kg of 1% or 2% solution; maximum single dose 4.5 mg/kg without epinephrine, 7 mg/kg with epinephrine; not recommended for children <12 years for certain blocks (e.g., epidural). |
| Geriatric use | Elderly patients may require lower doses (e.g., 50-75% of standard) due to reduced clearance and increased sensitivity; monitor for toxicity. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for NESACAINE (NESACAINE).
| Breastfeeding | Chloroprocaine is rapidly hydrolyzed in plasma by pseudocholinesterase; minimal amounts are excreted into breast milk. M/P ratio is not established. Use with caution in nursing mothers; unlikely to affect the infant due to rapid metabolism. |
| Teratogenic Risk | Chloroprocaine (Nesacaine) is a pregnancy category C drug. Animal reproduction studies have not been conducted. It should be used during pregnancy only if clearly needed. Inadvertent intravascular injection during labor may cause maternal and fetal toxicity. No known teratogenic effects have been reported with proper use in the first trimester. |
■ FDA Black Box Warning
None.
| Serious Effects |
["Hypersensitivity to chloroprocaine or other ester-type anesthetics","Hypersensitivity to PABA or parabens (cross-sensitivity)","Severe hemorrhage or hypotension","Infection at the injection site (for epidural use)"]
| Precautions | ["Risk of systemic toxicity (CNS and cardiovascular) from accidental intravascular injection","Avoid in patients with known pseudocholinesterase deficiency","Use with caution in patients with hepatic impairment or cardiac disease"] |
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| Fetal Monitoring | Continuous maternal ECG and blood pressure monitoring during administration. Fetal heart rate monitoring is recommended due to potential for uterine artery vasoconstriction or fetal bradycardia. Monitor for signs of systemic toxicity (metallic taste, tinnitus, seizures) and local anesthetic systemic toxicity (LAST). |
| Fertility Effects | No studies on fertility in humans. Animal studies have not been conducted to evaluate effects on fertility. No known significant impact on fertility or reproductive function. |