Lidocaine Dose Calculator

Calculate maximum safe lidocaine dose for local anesthesia with weight-based dosing

Calculate Maximum Lidocaine Dose

Patient body weight for dose calculation

Standard lidocaine concentrations available

Epinephrine increases maximum safe dose by reducing systemic absorption

Critical Medical Warning

This calculator provides maximum safe dosing guidelines only. Actual dosing must be determined by qualified medical professionals considering patient factors, injection site, and clinical conditions. Lidocaine toxicity can be life-threatening.

Lidocaine Clinical Information

Mechanism of Action

Sodium channel blocker: Prevents nerve signal transmission

Onset: 2-5 minutes after injection

Duration: 30-120 minutes (depending on epinephrine)

Half-life: 90-120 minutes

Clinical Applications

Minor surgery: Skin lesion removal, suturing

Dental procedures: Tooth extraction, fillings

Invasive procedures: Biopsies, catheter insertion

Pain management: Chronic pain conditions

Epinephrine Benefits

Vasoconstriction

Reduces bleeding at injection site

Longer Duration

Extends anesthetic effect 2-4x

Higher Safe Dose

Allows 7 mg/kg vs 4.5 mg/kg

Lidocaine Toxicity Signs

CNS

Central Nervous System

Confusion, seizures, drowsiness, tinnitus

CV

Cardiovascular

Bradycardia, hypotension, arrhythmias

RESP

Respiratory

Respiratory depression, apnea

LOCAL

Local Effects

Tissue necrosis, nerve damage

Contraindications

⚠️

Hypersensitivity to amide local anesthetics

🫀

Severe heart block (without pacemaker)

🩸

Methemoglobinemia, G6PD deficiency

🫁

Severe respiratory impairment

🔄

Wolff-Parkinson-White syndrome

Understanding Lidocaine Dosing

Maximum Safe Doses

Lidocaine dosing is calculated based on patient weight to prevent systemic toxicity. The maximum safe dose varies depending on whether epinephrine is included in the formulation.

Dosing Formulas

Without Epinephrine:

Maximum dose (mg) = 4.5 × weight (kg)

With Epinephrine:

Maximum dose (mg) = 7 × weight (kg)

Volume Calculation:

Volume (mL) = dose (mg) ÷ concentration (mg/mL)

Clinical Considerations

Patient Factors:

  • • Age and weight
  • • Cardiovascular status
  • • Liver function
  • • Concurrent medications
  • • Injection site vascularity

Clinical Pearl: Always aspirate before injection to avoid intravascular administration. Consider using ultrasound guidance for deep injections near major vessels or nerves to improve safety and efficacy.