Maximum Safe Dose of Lidocaine with Epinephrine
The maximum safe dose of lidocaine with epinephrine is 7.0 mg/kg for adults, as recommended by current dermatologic and pediatric guidelines. 1
Adult Dosing Guidelines
- Maximum dose of lidocaine with epinephrine: 7.0 mg/kg 1
- Maximum dose of lidocaine without epinephrine: 4.5 mg/kg 1
- For multistage procedures (e.g., Mohs surgery): Maximum 500 mg of lidocaine delivered incrementally over several hours 1
Pediatric Dosing Guidelines
- Maximum dose of lidocaine with epinephrine: 3.0-4.5 mg/kg 1
- Maximum dose of lidocaine without epinephrine: 1.5-2.0 mg/kg 1
- Doses should be decreased by 30% in infants younger than 6 months 1
Safety Considerations
Steps to Reduce Risk of Local Anesthetic Systemic Toxicity
- Use the lowest effective dose of local anesthetic
- Aspirate before each injection to avoid intravascular administration
- Administer incrementally rather than as a single bolus
- Continuously monitor and communicate with the patient for early signs of toxicity
- Have 20% lipid emulsion readily available when using higher doses 1
Early Signs of Toxicity
- Circumoral numbness
- Facial tingling
- Light-headedness
- Tinnitus
Special Anatomical Considerations
- Important: Absorption rates vary by anatomical location. Injections above the clavicles (face/neck) result in significantly faster absorption compared to lower extremities 2
- Peak plasma concentrations occur approximately 6 hours earlier with neck injections compared to thigh injections 2
Patient-Specific Factors Affecting Dosing
- Reduce doses in patients with:
- Hepatic impairment
- Renal dysfunction
- Cardiac disease
- Advanced age
- Pregnancy
Pharmacokinetic Considerations
- The addition of epinephrine (1:100,000 to 1:1,000) significantly delays lidocaine absorption, allowing for higher maximum doses 3
- Epinephrine causes vasoconstriction, reducing systemic absorption and prolonging local anesthetic effect
- The tissue pressure during injection does not significantly affect lidocaine absorption rates 3
Alternative Options for Lidocaine-Allergic Patients
- Ester-type local anesthetics
- 1% diphenhydramine injection
- Bacteriostatic normal saline (0.9% benzyl alcohol in normal saline) 1
While some research suggests higher doses may be safe in specific contexts like tumescent anesthesia (up to 28 mg/kg without liposuction and 45 mg/kg with liposuction) 4, these findings should not override the established guideline recommendations of 7.0 mg/kg for standard clinical practice, as these specialized techniques require specific expertise and monitoring protocols.