LIDOCAINE HYDROCHLORIDE 0.2% 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 local anesthetic that stabilizes neuronal membranes by inhibiting sodium ion influx, thereby blocking initiation and conduction of nerve impulses.
| Metabolism | Primarily hepatic via CYP1A2 and CYP3A4; also undergoes deethylation to monoethylglycinexylidide (MEGX) and further to glycinexylidide (GX). |
| Excretion | Renal: ~90% as metabolites and <10% unchanged. Biliary/fecal: minor (<1%). |
| Half-life | Terminal elimination half-life: 1.5-2 hours (adults); prolonged in heart failure (up to 4-6 hours) or hepatic impairment (up to 5-7 hours). |
| Protein binding | 60-80% bound to alpha-1-acid glycoprotein (AAG); varies with AAG concentration. |
| Volume of Distribution | Vd: 1.1-2.0 L/kg; increased to 2-4 L/kg in heart failure or hepatic disease. |
| Bioavailability | Intravenous: 100%; Intraosseous: ~100%; Oral: <35% due to extensive first-pass metabolism. |
| Onset of Action | Intravenous: 1-2 minutes; Intraosseous: similar to IV. |
| Duration of Action | Intravenous: 10-20 minutes (antiarrhythmic); continuous infusion required for sustained effect. |
| Molecular Weight | 270.8 |
1-1.5 mg/kg IV bolus over 2-3 minutes, followed by continuous IV infusion of 1-4 mg/min for ventricular arrhythmias; maximum 3 mg/kg (or 200-300 mg) over 1 hour.
| Dosage form | INJECTABLE |
| Renal impairment | No dose adjustment required; lidocaine clearance minimally affected by renal function. |
| Liver impairment | Child-Pugh Class A: no adjustment; Class B: reduce dose by 50%; Class C: avoid use or reduce dose by 75% with monitoring. |
| Pediatric use | Loading dose: 1-1.5 mg/kg IV/IO over 2-3 minutes; may repeat 0.5-0.75 mg/kg after 5-10 minutes (max 3 mg/kg). Maintenance infusion: 20-50 mcg/kg/min IV. |
| Geriatric use | Reduce infusion rate by 50% in elderly due to age-related decreased hepatic clearance; monitor for CNS toxicity and hypotension. |
| 1st trimester | Lidocaine crosses the placenta. Use only if clearly needed due to potential fetal bradycardia. No well-controlled studies in first trimester. |
| 2nd trimester | Lidocaine crosses the placenta. Use only if clearly needed. Monitor for fetal bradycardia. |
| 3rd trimester | Lidocaine can cause fetal bradycardia and CNS depression. Use only if maternal benefit outweighs fetal risk. |
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 via passive diffusion. Fetal to maternal ratio is approximately 0.5–0.7. Transfer is rapid, achieving fetal concentrations 50–70% of maternal levels. |
■ FDA Black Box Warning
None.
| Common Effects | ventricular arrhythmias |
| Serious Effects |
Hypersensitivity to lidocaine or amide-type local anestheticsSevere heart block (second or third degree) without pacemakerSevere hypotension or cardiogenic shockAcute porphyria (variegate or acute intermittent)
| Precautions | Risk of CNS toxicity (e.g., seizures, respiratory depression) and cardiotoxicity (e.g., bradycardia, hypotension) especially with high doses or rapid IV administration, Use with caution in patients with hepatic impairment, heart failure, or hypovolemia, Monitor ECG and vital signs during IV administration, May cause methemoglobinemia in neonates with repeated doses |
| Food/Dietary | No direct food interactions have been reported with lidocaine. However, grapefruit juice may theoretically affect CYP3A4 metabolism of lidocaine, though clinical significance is low. Avoid excessive caffeine or stimulants as they may increase cardiac side effects. |
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| Breastfeeding |
| Lidocaine is excreted into breast milk in small amounts. Oral bioavailability in infants is low, but caution is advised with high doses or prolonged use. Monitor infant for signs of toxicity such as drowsiness. |
| Lactation Rating | L2 (Safer) |
| Teratogenic Risk | Lidocaine crosses the placenta. For epidural use during labor, fetal heart rate changes may occur but it is not teratogenic at standard doses. FDA pregnancy category B. First trimester: No increased risk of major malformations. Second and third trimesters: No teratogenic effects reported; avoid high doses near delivery due to potential neonatal CNS depression. |
| Fetal Monitoring | Monitor maternal heart rate, blood pressure, and ECG for arrhythmias or CNS toxicity. For epidural use: fetal heart rate monitoring, maternal blood pressure (hypotension risk). Observe neonate for respiratory depression, bradycardia, and seizures if high doses given near delivery. |
| Fertility Effects | Lidocaine has no known effects on fertility in humans. Animal studies show no impairment of fertility at relevant doses. |
| Clinical Pearls | Lidocaine HCl 0.2% in D5W is typically used as a continuous intravenous infusion for management of ventricular arrhythmias, especially post-myocardial infarction. Monitor for CNS toxicity (seizures, confusion) and cardiac toxicity (bradycardia, hypotension). Reduce dose in hepatic impairment or heart failure. Contraindicated in severe sinoatrial, atrioventricular, or intraventricular block without pacemaker. Use preservative-free formulations for spinal or epidural anesthesia. |
| Patient Advice | This medication is used to treat irregular heartbeats. · It will be given intravenously by a healthcare professional. · Report any symptoms such as dizziness, drowsiness, confusion, seizures, or changes in heartbeat. · Avoid alcohol and other central nervous system depressants unless approved by your doctor. · Do not stop or change the dose without consulting your healthcare provider. |