LIDOCAINE HYDROCHLORIDE 0.4% IN DEXTROSE 5%
Clinical safety rating: safe
Beta-blockers may increase the risk of lidocaine toxicity Can cause CNS toxicity (seizures) and cardiovascular collapse.
Lidocaine is a class IB antiarrhythmic agent that blocks voltage-gated sodium channels, inhibiting phase 0 depolarization and decreasing automaticity in ventricular myocardial cells. It also has local anesthetic properties by blocking nerve impulse conduction.
| Metabolism | Hepatically metabolized primarily by cytochrome P450 1A2 (CYP1A2) to monoethylglycinexylidide (MEGX) and glycinexylidide (GX), both active metabolites. |
| Excretion | Renal excretion of metabolites (primarily monoethylglycinexylidide and glycinexylidide) accounts for >90% of elimination. Less than 10% excreted unchanged in urine. Biliary/fecal excretion is negligible. |
| Half-life | Terminal elimination half-life is approximately 1.5-2 hours (mean 1.8 h) in healthy adults. In patients with hepatic impairment or heart failure, half-life may be prolonged to >3 hours. In neonates, half-life can be 3-6 hours. |
| Protein binding | 70% bound primarily to alpha-1-acid glycoprotein (AAG), with some binding to albumin. Binding is concentration-dependent and decreases in conditions with low AAG (e.g., neonates) or high free fatty acids. |
| Volume of Distribution | Volume of distribution at steady state (Vdss) is approximately 1.1-1.6 L/kg in adults. Higher Vd (up to 2-3 L/kg) in neonates. Vd is increased in patients with hepatic cirrhosis or heart failure. |
| Bioavailability | Intravenous: 100% (by definition). Intramuscular: approximately 100%. Oral: <35% due to extensive first-pass metabolism. Not administered orally for systemic effect; only as topical or local anesthetic. |
| Onset of Action | Intravenous: 45-90 seconds; Intramuscular: 5-15 minutes; Subcutaneous infiltration: 2-5 minutes. Epidural: 5-15 minutes. |
| Duration of Action | Intravenous bolus: 10-20 minutes; Continuous IV infusion: duration depends on infusion rate; Intramuscular: 60-90 minutes; Subcutaneous infiltration: 30-60 minutes; Epidural: 60-90 minutes. Duration may be prolonged in patients with hepatic or cardiac disease. |
| Molecular Weight | 288.82 |
Intravenous infusion: 1-4 mg/min (0.25-1 mL/min of 0.4% solution) after a loading dose of 1-1.5 mg/kg IV bolus for ventricular arrhythmias. Maximum total dose: 3 mg/kg.
| Dosage form | INJECTABLE |
| Renal impairment | GFR 10-50 mL/min: No adjustment needed. GFR <10 mL/min: Reduce infusion rate by 50% due to metabolite accumulation. |
| Liver impairment | Child-Pugh class A: No adjustment. Child-Pugh class B: Reduce infusion rate by 50%. Child-Pugh class C: Avoid use or reduce infusion rate by 75% with monitoring. |
| Pediatric use | Neonates: Loading dose 1 mg/kg IV, infusion 20-50 mcg/kg/min. Children: Loading dose 1 mg/kg IV, infusion 20-50 mcg/kg/min. Maximum dose: 5 mg/kg total. |
| Geriatric use | Reduce infusion rate by 25-50% due to decreased clearance and increased risk of toxicity. Use lower loading doses. |
| 1st trimester | Lidocaine crosses the placenta. Use only if clearly needed and benefit outweighs risk. No known teratogenicity in human studies at usual doses. |
| 2nd trimester | Use only if clearly needed. Risk of fetal bradycardia with high doses or paracervical block. |
| 3rd trimester | Use only if clearly needed. Risk of fetal bradycardia, neonatal CNS depression, and methemoglobinemia with high doses or 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 | Lidocaine crosses the placenta by passive diffusion; fetal plasma concentrations are approximately 50-60% of maternal concentrations. |
| Breastfeeding |
■ FDA Black Box Warning
Not available (no FDA boxed warning for lidocaine hydrochloride 0.4% in dextrose 5%).
| Common Effects | ventricular arrhythmias |
| Serious Effects |
Hypersensitivity to lidocaine or any componentHypersensitivity to amide-type local anestheticsSevere heart block (Sinoatrial, atrioventricular, or intraventricular)Adams-Stokes syndromeUntreated sinus bradycardia
| Precautions | Cardiotoxicity: Risk of cardiac arrest, hypotension, bradycardia, and arrhythmias, especially with high doses or rapid administration, Central nervous system toxicity: Seizures, respiratory depression, and altered mental status, Use with caution in patients with hepatic impairment, heart failure, or elderly patients due to reduced clearance, Monitor for lidocaine toxicity (e.g., drowsiness, paresthesias, muscle twitching) |
| Food/Dietary |
Loading safety data…
| Lidocaine is excreted into breast milk in small amounts; levels are low and unlikely to cause adverse effects in the infant. Use caution with high maternal doses or prolonged infusion. |
| Lactation Rating | L2 (Safer) |
| Teratogenic Risk | Lidocaine crosses the placenta. First trimester: No well-controlled studies, but animal studies show no teratogenicity at clinically relevant doses. Second trimester: No known elevated risk of major malformations. Third trimester: Use in paracervical block can cause fetal bradycardia and acidosis. Avoid near term for obstetric anesthesia due to potential neonatal depression. |
| Fetal Monitoring | Continuous fetal heart rate monitoring during labor; maternal ECG for signs of systemic toxicity (e.g., QRS widening, arrhythmias); monitor maternal blood pressure and levels of consciousness. In prolonged infusion, monitor lidocaine levels (therapeutic 1.5-5 mcg/mL). |
| Fertility Effects | No evidence of adverse effects on fertility in animal studies or human data. Lidocaine does not impair spermatogenesis or oocyte maturation at clinical concentrations. |
| No significant food interactions. However, because this preparation contains dextrose, monitor blood glucose in diabetic patients. Avoid excessive alcohol consumption as it may potentiate CNS depression and lidocaine toxicity. |
| Clinical Pearls | This is a fixed-dose combination of lidocaine hydrochloride 0.4% (4 mg/mL) and dextrose 5% (50 mg/mL) used for intravenous administration. Lidocaine is a class Ib antiarrhythmic and local anesthetic. The dextrose provides a caloric source. Use in acute ventricular arrhythmias (e.g., ventricular tachycardia, ventricular fibrillation) and for local anesthesia during procedures. Monitor for CNS toxicity (dizziness, confusion, seizures) and cardiac toxicity (bradycardia, hypotension, arrhythmia). Adjust dose in hepatic impairment and heart failure. Do not use with other class I antiarrhythmics without caution. |
| Patient Advice | This medication is given intravenously, typically in a hospital setting, by a healthcare professional. · Report any symptoms such as dizziness, blurred vision, ringing in ears, numbness of the lips or tongue, or difficulty breathing immediately. · Avoid driving or operating machinery until you know how the medication affects you. · Inform your doctor of all medications you are taking, especially other heart medications and drugs that affect the liver. · Do not consume alcohol while taking this medication as it may increase the risk of side effects. |