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). |
| Molecular Weight | 234.34 |
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 | Lidocaine crosses the placenta. Use only if clearly needed; risk of fetal bradycardia or acidosis with high doses. |
| 2nd trimester | Use only if clearly needed; monitor for maternal and fetal effects. |
| 3rd trimester | Use only if clearly needed; may cause fetal bradycardia or CNS depression if administered near term. |
Clinical note
Beta-blockers may increase the risk of lidocaine toxicity Can cause CNS toxicity (seizures) and cardiovascular collapse.
| FDA category | Animal |
| Placental transfer | Rapidly crosses placenta by passive diffusion; fetal concentrations can reach 50-60% of maternal levels. |
| Breastfeeding |
■ FDA Black Box Warning
None.
| Common Effects | ventricular arrhythmias |
| Serious Effects |
Known hypersensitivity to lidocaine or amide-type anestheticsSevere heart block (without pacemaker)Severe hypotension or shockInfection at the injection site
| 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 |
| Food/Dietary | No known food interactions. However, patients on lidocaine should avoid alcohol consumption as it may increase the risk of CNS depression and hypotension. |
Loading safety data…
| Lidocaine is excreted into breast milk in small amounts (milk:plasma ratio ~0.4). It is considered compatible with breastfeeding, but monitor infant for drowsiness or feeding difficulties. |
| Lactation Rating | L2 (Probably Compatible) |
| Teratogenic Risk | 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. |
| Clinical Pearls | Lidocaine HCl preservative-free in plastic container is indicated for local or regional anesthesia. Note that the plastic container may leach DEHP; use within 24 hours of opening. In epidural anesthesia, test dose with epinephrine to detect intravascular injection. Avoid in patients with severe hypotension, complete heart block, or known hypersensitivity to amide anesthetics. Monitor for CNS toxicity (perioral numbness, metallic taste, seizures) and cardiac toxicity (QT prolongation, arrhythmias). Maximum dose without epinephrine: 4.5 mg/kg; with epinephrine: 7 mg/kg. In epidural use, reduce dose in elderly or debilitated. |
| Patient Advice | Inform your healthcare provider if you have heart disease, liver disease, or a history of allergic reactions to anesthetics. · You may experience temporary numbness, tingling, or weakness in the area where the medication is injected. · Report any symptoms such as ringing in the ears, metallic taste, dizziness, blurred vision, or difficulty breathing immediately. · Avoid driving or operating machinery until the effects of the medication wear off. |