Lidocaine with Epinephrine Dosage
For adults undergoing local anesthesia, the maximum safe dose is 7 mg/kg of lidocaine when combined with epinephrine, which translates to approximately 500 mg (50 mL of 1% solution) for a 70 kg patient. 1
Maximum Dose Guidelines
Adults
- Maximum dose: 7 mg/kg with epinephrine 1, 2
- Maximum dose without epinephrine: 4.5 mg/kg 1
- For extended procedures (e.g., Mohs surgery): up to 500 mg total delivered incrementally over 8 hours 1
- The addition of epinephrine increases the safe dose by 55% compared to plain lidocaine 2
Pediatric Patients
- Maximum dose: 3.0-4.5 mg/kg with epinephrine 1, 2
- Maximum dose without epinephrine: 1.5-2.0 mg/kg 1
- Critical: Reduce all doses by 30% in infants under 6 months of age 2
Practical Conversion
- 1% lidocaine = 10 mg/mL 2
- For a 70 kg adult: maximum 49 mL of 1% lidocaine with epinephrine (7 mg/kg × 70 kg = 490 mg ÷ 10 mg/mL) 1
Epinephrine Concentration Recommendations
Use the lowest effective concentration of epinephrine, with 1:200,000 preferred over 1:100,000 for most procedures. 1
- Concentrations of 1:50,000,1:100,000, and 1:200,000 provide equivalent vasoconstriction and prolong anesthetic duration by approximately 200% 1, 3
- 1:200,000 epinephrine causes less hemodynamic disturbance (blood pressure and heart rate changes) than 1:100,000 while maintaining equal efficacy 4
- More dilute concentrations (1:800,000 to 1:3,200,000) provide less effective vasoconstriction 1
- Wait 8-10 minutes after injection before making incisions to allow maximal vasoconstriction 5
Safety Precautions to Prevent Toxicity
Pre-Procedure Calculations
- Calculate the maximum allowable dose in milligrams before starting the procedure 2
- Use ideal body weight for dose calculations, especially in obese patients 2
- Track cumulative dose throughout the procedure 2
During Administration
- Aspirate before each injection to avoid intravascular administration 2, 6
- Use incremental injections rather than bolus dosing 2
- Inject slowly to minimize systemic absorption 6
- Use reduced doses in highly vascular areas 2
Monitoring for Toxicity
- Early signs: circumoral numbness, facial tingling, metallic taste, slurred speech 1, 2
- Progressive signs: auditory changes, hallucinations, hypertension, tachycardia 1
- Severe toxicity: seizures, CNS depression, cardiac arrest 1
Special Populations and Situations
Cardiac Disease
- Epinephrine in small amounts is safe for patients with stable, controlled cardiovascular disease 1
- Consult cardiology if uncertain about patient's ability to tolerate epinephrine 1
- The American Academy of Dermatology supports this based on dental literature showing safety with 1.8-3.6 mL of lidocaine 2% with epinephrine 1:80,000 to 1:200,000 1
Pregnancy
- Epinephrine may be used in small amounts during pregnancy 1
- Postpone elective procedures until after delivery 1
- Delay urgent procedures until second trimester when possible 1
- Consult obstetrics when using large amounts of anesthesia 1
Anatomical Considerations
Common Pitfalls and How to Avoid Them
- Dosing error: Always convert percentage to mg/mL (1% = 10 mg/mL) before calculating maximum volume 2
- Weight miscalculation: Use ideal body weight, not actual body weight, particularly in obese patients 2
- Cumulative toxicity: Track total dose over time in prolonged procedures; do not exceed 500 mg over 8 hours 1
- Drug interactions: Avoid administering within 4 hours of other local anesthetic interventions 6, 7
- Enhanced sedation: Expect increased sedative effects when combining maximum doses with opioids or other sedatives 2
Dose Reduction for Special Routes
For intravenous regional anesthesia (Bier block), maximum dose drops dramatically to 3-5 mg/kg 2