What are the uses of intravenous (IV) lidocaine at a dose of 1-1.5 milligrams per kilogram (mg/kg)?

Uses of IV Lidocaine 1-1.5 mg/kg

IV lidocaine at 1-1.5 mg/kg is primarily used as a loading dose for perioperative analgesia, neuropathic pain management, and status migraine treatment, administered as an infusion over 10 minutes (never as a bolus) followed by continuous infusion for maintenance. 1, 2

Primary Clinical Applications

Perioperative Pain Management

• IV lidocaine serves as part of multimodal analgesia for postoperative pain control, particularly effective in abdominal and orthopedic surgeries 1, 3
• The 1.5 mg/kg loading dose should be given over 10 minutes after anesthesia induction, followed by maintenance infusion of 1.5-2 mg/kg/hour intraoperatively 3, 4
• Reduces opioid requirements significantly in the acute postoperative period—patients undergoing arthroscopic rotator cuff repair showed lower fentanyl consumption (329 vs 394.5 µg in 24 hours) with lidocaine infusion 4
• Provides additional benefits beyond analgesia including improved intestinal motility and anti-inflammatory effects through inhibition of neutrophilic granulocyte priming 3

Neuropathic Pain Treatment

• IV lidocaine demonstrates efficacy for opioid-refractory cancer pain and neuropathic pain conditions 1
• The analgesic response occurs over a narrow concentration range (0.62 µg/mL), characterized by a precipitous "break in pain" rather than gradual dose-response 5
• The ED50 is 372 mg with ED90 at 416.5 mg—only a 44.5 mg difference, indicating a steep dose-response curve requiring careful titration 5

Status Migraine in Pediatrics

• IV lidocaine (2.9 mg/kg bolus followed by 1.29 mg/kg/hour infusion) effectively treats status migraine in children and adolescents aged 10-19 years 6
• Pain resolution occurred in 90.3% of cases, with 50% pain reduction achieved in average 16.3 hours 6
• Mean pain scores dropped from 5.1 on day 1 to 1.0 on day 5 of therapy 6

Anesthesia Adjunct

• Pre-induction IV lidocaine 1.5 mg/kg reduces propofol requirements by approximately 27% (110.8 mg vs 151.2 mg in controls) 7
• Should be administered 2 minutes before propofol induction 7

Critical Safety Parameters

Dosing Calculations and Limits

• Always calculate dose using ideal body weight, not actual body weight (Men: height in cm - 100; Women: height in cm - 105) 1, 2
• Never exceed 1.5 mg/kg for loading dose 1, 2
• Maximum hourly rate: 120 mg/hour regardless of patient weight 1, 2
• Do not use in patients weighing less than 40 kg 1, 2
• Maximum total dose without epinephrine: 4.5 mg/kg in adults, 1.5-2.0 mg/kg in children 8, 9

Administration Requirements

• Administer through a dedicated, separate IV cannula with proper line labeling 2
• Loading dose must be given over 10 minutes as an infusion, never as a rapid bolus 1, 2
• Anesthesiologist must be present during initial loading dose 1
• Continuous ECG monitoring, pulse oximetry, and blood pressure checks every 5 minutes during loading and first 15 minutes thereafter 1, 2

Duration and Pharmacokinetic Considerations

• Limit infusion duration to maximum 24 hours 1
• Lidocaine exhibits time-dependent pharmacokinetics: half-life is 100 minutes for infusions <12 hours but increases to 3.22 hours after 24 hours 10
• After 24 hours, infusion rate should be reduced by approximately 50% even in patients without cardiac or hepatic failure 10

Critical Contraindications and Timing Restrictions

Local Anesthetic Interactions

• Do not administer IV lidocaine within 4 hours of any nerve block or fascial plane block 1, 2
• Do not perform nerve blocks until 4 hours after discontinuing IV lidocaine infusion 1, 2
• Remove topical 5% lidocaine plasters before starting infusion 2, 8
• Single-shot spinal blockade is permissible concurrently due to minimal local anesthetic dose 2

Relative Contraindications

• Electrolyte disorders, seizure disorders, renal or hepatic impairment 2
• Pregnancy/breastfeeding, neurological disorders 2
• Advanced liver failure (absolute contraindication due to decreased clearance) 8

Toxicity Recognition and Management

Early Warning Signs

• Perioral numbness, facial tingling, tinnitus, metallic taste 1, 2
• Slurred speech, light-headedness, visual disturbances 1, 2
• Toxic plasma concentrations occur at 9-10 µg/mL 10

Progressive Toxicity

• Muscle twitching, confusion, loss of consciousness 1, 2
• Respiratory arrest, myocardial depression 2
• Cardiac arrhythmias, ventricular arrest 2

Emergency Preparedness

• Lipid emulsion 20% must be readily available wherever IV lidocaine is administered 1
• Patients receiving lidocaine outside operating room/recovery should be in monitored high dependency unit 1

Factors Increasing Toxicity Risk

Patient-Related Factors

• Acidemia increases free drug by enhancing dissociation from plasma proteins 10
• Hypoalbuminemia and protein depletion increase free plasma drug concentration 10
• Low skeletal muscle mass reduces drug reservoir capacity 10
• High BMI patients may have inadvertently higher plasma concentrations when actual rather than ideal body weight is used for dosing 10

Drug Interactions

• Beta-blockers reduce lidocaine metabolism 10
• Amiodarone decreases clearance, particularly problematic with prolonged infusions 10
• Cytochrome P450 inducers and inhibitors affect metabolism 10