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 |
| Molecular Weight | 307.17 |
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 | Avoid use during first trimester due to limited safety data and potential fetal effects. Lidocaine derivatives are generally preferred. |
| 2nd trimester | Use only if clearly needed; limited data but no major teratogenic risk identified. Monitor for maternal and fetal bradycardia. |
| 3rd trimester | Use with caution near term; may cause neonatal bradycardia, hypotonia, or acidosis. Avoid in cases of fetal distress. |
Clinical note
Comprehensive clinical and safety monograph for NESACAINE (NESACAINE).
| Placental transfer | Rapidly crosses placenta; degree of transfer is moderate but cleared quickly by fetal plasma esterases. |
| Breastfeeding | Chloroprocaine is rapidly metabolized in plasma with a short half-life (21 seconds). Minimal excretion into breast milk is expected. The American Academy of Pediatrics considers chloroprocaine compatible with breastfeeding. Use caution in neonates due to theoretical risk of methemoglobinemia. |
■ FDA Black Box Warning
None.
| Serious Effects |
Hypersensitivity to chloroprocaine or other ester-type anestheticsSulfite allergy (product may contain sodium metabisulfite)Severe hypotension or shockInfection at injection siteCoagulopathy or anticoagulant therapy (for neuraxial 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 |
| Food/Dietary | No known food interactions with NESACAINE. Avoid alcoholic beverages during effect of local anesthesia. |
| Clinical Pearls |
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| Lactation Rating | L2 (Safer if appropriate use) |
| 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. |
| 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. |
| NESACAINE (chloroprocaine) is an ester-type local anesthetic with rapid onset and short duration. It contains methylparaben; avoid in patients with known paraben allergy. Use with caution in patients with pseudocholinesterase deficiency. Epidural administration may produce hypotension; monitor blood pressure. Contraindicated in patients with myasthenia gravis due to potential for prolonged neuromuscular blockade. |
| Patient Advice | Report any signs of allergic reaction such as rash, itching, or difficulty breathing. · Inform your doctor if you have liver disease, kidney disease, or a history of allergic reactions to anesthetics. · Avoid driving or operating machinery until the effects of the anesthetic wear off. · Do not consume alcohol while under the influence of this medication. · Temporary numbness or loss of sensation in the treated area is expected. |