CHIROCAINE
Clinical safety rating: caution
Comprehensive clinical and safety monograph for CHIROCAINE (CHIROCAINE).
Chirocaine (levobupivacaine) is a long-acting local anesthetic of the amide type. It blocks sodium channels, inhibiting nerve impulse initiation and conduction, thereby producing local anesthesia.
| Metabolism | Primarily hepatic via cytochrome P450 enzymes, mainly CYP3A4 and CYP1A2, with minor contributions from CYP2C19 and CYP2D6. |
| Excretion | Renal excretion accounts for approximately 95% of the dose, with most being eliminated as metabolites (mainly p-aminobenzoic acid and other conjugates) and less than 5% as unchanged drug. Biliary/fecal excretion is minimal (<5%). |
| Half-life | Terminal elimination half-life is 0.5–1.5 hours (adults) and 1–2 hours (neonates). Clinically, this short half-life limits accumulation with repeated doses. |
| Protein binding | Approximately 95% bound, primarily to alpha-1-acid glycoprotein (AAG) and, to a lesser extent, albumin. |
| Volume of Distribution | Vd: 1.0–1.5 L/kg. Clinical meaning: Indicates extensive tissue distribution; higher Vd in neonates (up to 2–3 L/kg). |
| Bioavailability | Not applicable orally (undergoes extensive first-pass metabolism). Bioavailability after epidural or local administration is essentially 100% locally; systemic absorption depends on injection site and vascularity. |
| Onset of Action | Epidural: 10–20 min; Caudal: 10–15 min; Peripheral nerve block: 15–30 min; Infiltration: 1–5 min; Spinal: immediate to 5 min. |
| Duration of Action | Epidural: 1–3 hours; Caudal: 2–4 hours; Peripheral nerve block: 2–6 hours; Infiltration: 0.5–2 hours. Duration is prolonged with epinephrine. |
0.5% to 0.75% solution; epidural: 10-20 mL of 0.5% solution (50-100 mg) as initial dose; for surgical anesthesia, 15-20 mL of 0.75% solution (112.5-150 mg); repeat doses of 0.25% to 0.5% solution at 40-60 minute intervals as needed. Maximum single dose: 225 mg.
| Dosage form | INJECTABLE |
| Renal impairment | No specific dose adjustment required for renal impairment; use with caution in severe renal disease due to potential accumulation of metabolites. |
| Liver impairment | Child-Pugh Class A: no adjustment; Child-Pugh Class B: reduce dose by 50% or use alternative; Child-Pugh Class C: contraindicated or use with extreme caution, monitor for toxicity. |
| Pediatric use | Neonates and infants: dose not established; children <12 years: use 0.25-0.5% solution, maximum 2-3 mg/kg; administer as intermittent boluses or continuous infusion; avoid use in neonates due to increased risk of systemic toxicity. |
| Geriatric use | Reduce initial dose by 25-50% due to decreased clearance and increased sensitivity; monitor for cardiovascular and neurological effects; use lower concentrations (0.25-0.5%) and lower volumes. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for CHIROCAINE (CHIROCAINE).
| Breastfeeding | Levobupivacaine is excreted into human breast milk in very small amounts; the milk-to-plasma (M/P) ratio is approximately 0.3. At therapeutic doses, exposure to the nursing infant is negligible. The American Academy of Pediatrics considers its use compatible with breastfeeding. However, caution is advised with prolonged use or high doses. |
| Teratogenic Risk | Chirocaine (levobupivacaine) is classified as FDA Pregnancy Category B. Animal studies have not demonstrated teratogenic effects. There are no adequate and well-controlled studies in pregnant women. Use during the first trimester is not associated with increased risk of major congenital malformations. During the second and third trimesters, caution is advised due to potential maternal hypotension and fetal bradycardia following regional anesthesia. Use only if clearly needed. |
■ FDA Black Box Warning
Use in obstetric epidural anesthesia has been associated with rare but serious adverse events including cardiac arrest and death, especially with high doses or unintentional intravascular injection. Resuscitation may be difficult.
| Serious Effects |
["Known hypersensitivity to amide-type local anesthetics","Severe hypotension or hypovolemia","Cardiac conduction abnormalities (e.g., AV block, Wolff-Parkinson-White syndrome)","Infection at injection site","Severe bleeding disorders or anticoagulant therapy (relative contraindication for neuraxial use)"]
| Precautions | ["Cardiotoxicity: May cause QT prolongation, arrhythmias, and cardiac arrest; avoid rapid IV administration.","CNS toxicity: Seizures, loss of consciousness; risk increased with accidental intravascular injection.","Neurological injury: Risk with spinal administration; use lowest effective dose.","Hypersensitivity: Can occur; discontinue if signs appear.","Use caution in hepatic impairment, elderly, debilitated, or convalescent patients."] |
| Food/Dietary | No known food interactions with Chirocaine. Avoid excessive alcohol consumption, which may potentiate central nervous system effects. |
Loading safety data…
| Fetal Monitoring | Monitor maternal blood pressure, heart rate, and oxygen saturation continuously during administration. Monitor fetal heart rate patterns if applicable. Observe for signs of local anesthetic systemic toxicity (LAST) including central nervous system and cardiovascular effects. Assess for maternal hypotension and treat promptly to maintain uteroplacental perfusion. |
| Fertility Effects | No adequate studies on fertility effects. Animal studies have not shown impaired fertility at doses up to 30 mg/kg/day. In humans, no evidence of adverse effects on reproductive function. However, as with other local anesthetics, high systemic levels may theoretically affect uterine tone and blood flow. |
| Clinical Pearls | Chirocaine (levobupivacaine) is a long-acting amide local anesthetic with a safer cardiac and CNS toxicity profile compared to racemic bupivacaine. It is approximately 30% less potent than bupivacaine; adjust dosing accordingly. Use with caution in hepatic impairment due to metabolism by CYP3A4 and CYP1A2. Avoid intravascular injection; always aspirate before injection. For epidural use, test dose with epinephrine is recommended to detect inadvertent intravascular administration. |
| Patient Advice | Report any numbness, tingling, or weakness in limbs after injection. · Alert your doctor if you experience difficulty breathing, chest tightness, or metallic taste. · Do not drive or operate machinery until the effects wear off completely. · Inform your doctor if you have liver disease, heart problems, or are taking medications like cimetidine or beta-blockers. · If numbness persists longer than expected, consult your healthcare provider. |