Lidocaine

See critical care quick reference for drug doses by weight.

General

  • Also known internationally as lignocaine
  • Type: Local anesthetics; Antiarrhythmics
  • Dosage Forms: Local injection, transdermal, intravenous, inhaled, viscous
  • Common Trade Names: Xylocaine, P-Care, ReadySharp Lidocaine, Xylocard [1]

Adult Dosing

Local Anesthetic

  • Maximum without epinepherine: 5mg/kg (max 300mg)
  • Maximum with epinepherine: 7mg/kg (max 500mg)

Antiarrhythmic

  • Loading dose = 1-1.5mg/kg
    • Additional boluses of 0.5-0.75mg/kg q5-10min up to max of 3mg/kg
    • If effective start infusion of 2mg/min
  • Indications

Pediatric Dosing

Local Anesthetic

  • Without epinepherine: 5mg/kg (max 300mg)
  • With epinepherine: 7mg/kg (max 500mg)

Antiarrhythmic

See critical care quick reference for drug doses by weight.

Special Populations

  • Pregnancy Rating: American B, Australia A
  • Lactation: Not expected to cause any adverse effect [2]
  • Renal Dosing
    • Adult: No adjustment provided in manufacturer's labelling but accumulation of metabolites may be increased in renal dysfunction[3]
    • Pediatric: No adjustment provided in manufacturer's labelling [4]
  • Hepatic Dosing
    • Adult: Reduce maintenance infusion when used IV (0.75 mg/minute). Monitor concentration.[5]
    • Pediatric: Use with caution. Reduce dose. [6]

Contraindications

  • Allergy to amide anesthetics
    • Note that these allergies are rare and are often caused by preservative, so a preservative-free formulation may be appropriate
    • Note that allergy to amide anesthetics does not suggest allergy to ester anesthetics
  • High SA or AV block (without pacemaker)
  • Concurrent treatment with Class I anti-dysrhythmic agents
  • Wolff-Parkinson-White syndrome

Adverse Reactions

Local

  • Dermatologic
    • Itching or irritation
    • Depigmentation
    • Rash/urticaria
    • Edema
    • Venous inflammation

Serious

  • Local Anesthetic Systemic Toxicity (LAST)
    • Rare during infiltration of local anesthetic
    • CNS toxicity
      • Metallic taste
      • Tinnitus
      • Tingling of lips
      • Dizziness
      • Anxiety
      • Confusion
      • Lethargy
      • Loss of consciousness
      • Seizures
      • Nausea/vomiting
    • Cardiovascular toxicity
      • Bradycardia
      • Decreased myocardial contractility
      • Atrioventricular block
      • Vasodilation
      • Ventricular arrhythmias
      • Cardiac arrest
  • Bronchospasm
  • Respiratory depression or arrest
  • Methemoglobinemia

Pharmacology

  • Pharmacokinetics
    • Onset of action = 45-90s
    • Duration of action = 10-20min (antiarrythmic IV); 30-90 min (subcutaneous)
    • Half-life 90 - 120 minutes
      • Prolonged in hepatic impairment or congestive heart failure
  • Metabolism
    • Primarily hepatic
  • Excretion
    • Urine
  • Mechanism of Action
    • Class Ib antiarrythmic
      • Binds to fast Na channels in inactive state thereby raising the depolarization threshold
      • Acts preferentially on ischemic tissue
        • Elevates V-fib threshold
        • Suppresses ventricular ectopy
    • Little effect on vascular tone, contractility, or cardiac output

Comments

  • To decrease pain on injection for local anesthesia, may use bicarbonate buffered solution (!:10 cc)
    • Shorter shelf-life due to decreased stability
  • Inject through wound edges whenever possible
    • Avoid injecting through intact skin when possible

See Also

References

  1. Lidocaine. Lexicomp. Wolters Kluwer Health, Inc. Riverwoods, IL. Accessed March 15, 2019
  2. https://www.ncbi.nlm.nih.gov/books/NBK501230/
  3. Lidocaine. Lexicomp. Wolters Kluwer Health, Inc. Riverwoods, IL. Accessed March 15, 2019
  4. Lidocaine. Lexicomp. Wolters Kluwer Health, Inc. Riverwoods, IL. Accessed March 15, 2019
  5. Lidocaine. Lexicomp. Wolters Kluwer Health, Inc. Riverwoods, IL. Accessed March 15, 2019
  6. Lidocaine. Lexicomp. Wolters Kluwer Health, Inc. Riverwoods, IL. Accessed March 15, 2019