LIDOCAINE HYDROCHLORIDE PRESERVATIVE FREE IN PLASTIC CONTAINER
Clinical safety rating: safe
Beta-blockers may increase the risk of lidocaine toxicity Can cause CNS toxicity (seizures) and cardiovascular collapse.
Lidocaine is an amide-type local anesthetic that stabilizes neuronal membranes by blocking voltage-gated sodium channels, thereby inhibiting the initiation and conduction of nerve impulses. It exhibits antiarrhythmic activity by suppressing automaticity and conduction in cardiac tissues.
| Metabolism | Primarily hepatic metabolism via CYP1A2 and CYP3A4 to active metabolites (monoethylglycinexylidide, glycinexylidide); approximately 90% undergoes dealkylation; <10% excreted unchanged in urine. |
| Excretion | Renal: ~90% as metabolites (including monoethylglycinexylidide [MEGX] and glycinexylidide [GX]) and ~10% unchanged. Biliary/fecal: <3%. |
| Half-life | Terminal elimination half-life: 1.5–2 hours (normal cardiac output and hepatic function). Prolonged in heart failure (up to 10 hours), hepatic disease (up to 5–15 hours), and with continuous infusion (due to saturable metabolism). |
| Protein binding | 70% bound mainly to alpha-1-acid glycoprotein (AAG) and albumin. Binding decreases in conditions with low AAG (e.g., neonates, pregnancy) leading to higher free fraction. |
| Volume of Distribution | Vd: 1–1.5 L/kg (healthy adults). Increased in heart failure (1.5–2 L/kg) and decreased in neonates (0.5–0.8 L/kg). |
| Bioavailability | Intravenous: 100%; Intramuscular: 100% (rapid absorption); Oral: <35% (extensive first-pass hepatic metabolism); Topical: variable, up to 10% (mucous membranes) and <1% (intact skin). |
| Onset of Action | Intravenous: 45–90 seconds; Intramuscular: 5–15 minutes; Epidural: 5–15 minutes; Topical: 2–5 minutes (mucous membranes), up to 60 minutes (intact skin). |
| Duration of Action | Intravenous: 10–20 minutes (single bolus); Epidural: 60–90 minutes (with epinephrine prolonged to 90–120 minutes); Peripheral nerve block: 60–120 minutes (with epinephrine up to 200 minutes); Topical: 30–60 minutes (mucous membranes). |
Antiarrhythmic: 1-1.5 mg/kg IV bolus, may repeat 0.5-0.75 mg/kg in 5-10 minutes; maximum total 3 mg/kg. Followed by continuous IV infusion 1-4 mg/min. Local anesthesia: maximum 4.5 mg/kg (300 mg) without epinephrine; 7 mg/kg (500 mg) with epinephrine.
| Dosage form | INJECTABLE |
| Renal impairment | No dosage adjustment required for renal impairment; lidocaine is extensively hepatically metabolized. |
| Liver impairment | Child-Pugh Class A: No adjustment. Child-Pugh Class B: Reduce infusion rate by 50%. Child-Pugh Class C: Avoid continuous infusion or reduce dose by 75% and monitor levels. |
| Pediatric use | Antiarrhythmic: IV bolus 1 mg/kg; may repeat in 5-10 minutes; maximum total 3 mg/kg. Continuous IV infusion 20-50 mcg/kg/min. Local anesthesia: 4-5 mg/kg maximum dose. |
| Geriatric use | Reduce initial loading dose and infusion rate by 50% due to decreased clearance; monitor for toxicity. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Beta-blockers may increase the risk of lidocaine toxicity Can cause CNS toxicity (seizures) and cardiovascular collapse.
| FDA category | Animal |
| Breastfeeding | Lidocaine is excreted into breast milk with a milk-to-plasma ratio of approximately 0.4. The relative infant dose is less than 4% of the maternal weight-adjusted dose. Transient adverse effects are unlikely at usual maternal doses. However, monitor infant for signs of toxicity (e.g., irritability, feeding difficulties) if high doses or prolonged infusions are used. |
| Teratogenic Risk |
■ FDA Black Box Warning
None.
| Common Effects | ventricular arrhythmias |
| Serious Effects |
["Hypersensitivity to lidocaine, amide-type anesthetics, or any component","Severe heart block (second- or third-degree AV block) without pacemaker","Adams-Stokes syndrome","Patients with porphyria (amides may be porphyrinogenic)"]
| Precautions | ["Risk of systemic toxicity (CNS, cardiovascular) with excessive dosing or rapid absorption","Use with caution in patients with hepatic impairment (reduced clearance)","Avoid intravascular injection to prevent severe cardiac depression or arrest","Monitor for signs of CNS toxicity: confusion, seizures, respiratory depression","Use reduced doses in elderly or debilitated patients"] |
Loading safety data…
| Lidocaine crosses the placenta. No increased risk of major malformations has been observed in human studies after first-trimester exposure. Fetal bradycardia, acidosis, and CNS depression may occur with high maternal doses or if used near term, especially with paracervical block. Avoid paracervical block in pregnancy due to risk of fetal bradycardia. Use only if clearly needed. |
| Fetal Monitoring | Monitor maternal ECG, blood pressure, and respiratory status during IV infusion. Monitor fetal heart rate during paracervical block or high-dose therapy. Assess for signs of CNS toxicity (seizures, drowsiness) and cardiovascular instability in both mother and fetus. Adjust rate or discontinue if signs of toxicity occur. |
| Fertility Effects | No adequate studies on fertility in humans. Animal studies show no evidence of impaired fertility. Lidocaine is not expected to affect fertility at therapeutic doses. |