Maximum Lidocaine Doses Without Epinephrine
For plain lidocaine (2% solution), the maximum dose is 4.5 mg/kg, not exceeding 300 mg total in adults. This applies to infiltration, nerve blocks, or topical use in procedures like minor surgery or dental work.[1][2]
Maximum Lidocaine Doses With Epinephrine
Adding epinephrine (1:100,000 or 1:200,000) extends safe limits to 7 mg/kg, up to 500 mg total. Epinephrine causes vasoconstriction, slowing absorption and reducing toxicity risk. Common in longer procedures like skin biopsies or joint injections.[1][3]
| Patient Group | Plain Lidocaine (mg/kg, max total) | With Epinephrine (mg/kg, max total) |
|---------------|------------------------------------|-------------------------------------|
| Adults | 4.5 mg/kg, 300 mg | 7 mg/kg, 500 mg |
| Children | 4.5 mg/kg (adjust by weight) | 7 mg/kg (adjust by weight) |
| Elderly/Debilitated | Lower: 2-4 mg/kg | Lower: 4-6 mg/kg |
How to Calculate Doses for Procedures
Multiply patient weight (kg) by mg/kg limit, then cap at total max. Example: 70 kg adult with epinephrine: 70 × 7 = 490 mg (under 500 mg limit). Use 1% or 2% solutions; 1 mL of 1% = 10 mg, 1 mL of 2% = 20 mg. For a 10 mL syringe of 2% with epi: 200 mg total.[2][4]
Why These Limits Exist: Toxicity Risks
Exceeding doses risks CNS (tinnitus, seizures) or cardiac toxicity (arrhythmias, hypotension). Symptoms start at 5-7 mg/kg plasma levels. Monitor for 30-60 minutes post-injection; IV lipids reverse severe cases. Obese patients use ideal body weight for calculation.[1][3]
Differences by Procedure Type
- Dental: Up to 8 cartridges (1.8 mL 2% with epi = ~68 mg/cartridge), total ~430 mg safe.[4]
- Topical (e.g., EMLA cream): 5 mg/kg (2.5 g 2.5% cream), max 3 g adults.[2]
- IV Regional (Bier Block): 3-4 mg/kg plain, single arm only.[3]
- Spinal/Epidural: 50-100 mg total, diluted.[1]
Special Populations and Adjustments
Reduce by 20-50% in liver disease, heart failure, or acidosis (slows metabolism). Pediatrics: Strict weight-based, no exceedance. Pregnancy: Category B, use lowest effective dose.[2][5]
What Happens If You Exceed the Dose
Mild: Dizziness, perioral numbness. Severe: Convulsions, coma, cardiac arrest. Treat with airway support, benzos for seizures, lipid emulsion (1.5 mL/kg 20% Intralipid).[3][6]
[1]: ASRA Guidelines on Local Anesthetics
[2]: FDA Lidocaine Label
[3]: UpToDate: Local Anesthetic Systemic Toxicity
[4]: ADA Dental Anesthesia Guidelines
[5]: Lexicomp: Lidocaine Dosing
[6]: ASRA LAST Checklist