Recommended Dosage for Topical Lidocaine
The maximum safe dose of topical lidocaine is 4.5 mg/kg without epinephrine and 7.0 mg/kg with epinephrine for adults, and 1.5-2.0 mg/kg without epinephrine and 3.0-4.5 mg/kg with epinephrine for children. 1
General Dosing Guidelines
Adult Dosing
- Maximum dose: 4.5 mg/kg without epinephrine; 7.0 mg/kg with epinephrine 1
- For intravenous lidocaine: Maximum 1.5 mg/kg loading dose over 10 minutes, followed by 1.5 mg/kg/h infusion 2
- For awake tracheal intubation: Maximum dose should not exceed 9 mg/kg lean body weight 2
Pediatric Dosing
- Maximum dose: 1.5-2.0 mg/kg without epinephrine; 3.0-4.5 mg/kg with epinephrine 1
- Children <12 months or weighing <10 kg require lower doses 2
- Contraindicated in patients weighing <40 kg for IV infusions 2
Application-Specific Recommendations
Topical Anesthesia for Procedures
- Apply topical lidocaine 30-40 minutes before procedure for optimal effect 3
- For facial application: 2.5-5g of 4% lidocaine cream is typically sufficient 4
- For oral mucosa: Maximal hypoalgesia reached 4-5 minutes after application, lasting until 14 minutes; optimal procedure window is 3-8 minutes after application 5
Airway Procedures
- For bronchoscopy: Aerosolized lidocaine (50mg of 2% solution) can reduce the total dose needed for the procedure 6
- For awake tracheal intubation: Use the lowest effective dose, not exceeding 9 mg/kg lean body weight 2
Important Safety Considerations
Risk Factors for Toxicity
- Occlusive dressings can triple serum lidocaine levels compared to non-occlusive application 4
- Significant interindividual variability exists in lidocaine absorption and metabolism 7
- Different formulations with the same lidocaine concentration can result in different serum levels 7
Contraindications
- Active infections at the application site
- True lidocaine allergy
- Uncontrolled diabetes, severe hypertension, heart failure
- Neurological disorders 1
- For EMLA: Recent sulfonamide antibiotic use, congenital or idiopathic methemoglobinemia 2
Monitoring
- Watch for early signs of toxicity: circumoral numbness, facial tingling, light-headedness, tinnitus 1
- For IV lidocaine: Continuous ECG, pulse oximetry, and regular blood pressure monitoring 2
- Test adequacy of topicalization in an atraumatic manner before airway instrumentation 2
Special Considerations
- Do not use topical lidocaine concurrently with other local anesthetic interventions
- Wait at least 4 hours between topical lidocaine and nerve/fascial plane blocks 2
- For patches: Apply to intact skin only, up to 3-4 patches for 12 hours in a 24-hour period 1
- When calculating doses, use ideal body weight rather than actual body weight 2
By following these dosing guidelines and safety precautions, topical lidocaine can provide effective local anesthesia while minimizing the risk of systemic toxicity.