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Name: Lidocaine Hydrochloride

Pregnancy Category B

Drug classes

  • Antiarrhythmic
  • Local anesthetic

Mechanisms of  actions

Type 1 antiarrhythmic: decreases diastolic depolarization, decreasing automaticity of ventricular cells; increases ventricular fibrillation threshold.

Local anesthetic: blocks the generation and conduction of action potentials in sensory nerves by reducing sodium permeability, reducing height and rate of rise of the action potential, increasing excitation threshold,
and slowing conduction velocity.


As antiarrhythmic: Management of acute ventricular arrhythmias during cardiac surgery and MI (IV use). Use IM when IV administration is not possible or when ECG monitoring is not available and the danger of ventricular arrhythmias isgreat (single-dose IM use, for example, by paramedics in a mobile coronary care unit).

As anesthetic: Infiltration anesthesia, peripheral and sympathetic nerve blocks, central nerve blocks, spinal and caudal anesthesia, retrobulbar and transtracheal injection; topical anesthetic for skin disorders and accessible mucous membranes


Contraindicated in the presence of allergy to lidocaine or amide-type local anesthetics, CHF, cardiogenic shock, second- or third-degree heart block (if no artificial pacemaker), Wolff-Parkinson-White syndrome, Stokes-Adams syndrome.

Use caution in the presence of hepatic or renal disease, inflammation or sepsis in the region of injection (local anesthetic), labor and delivery (epidural anesthesia may prolong the second stage of labor; monitor for fetal and neonatal CVS and CNS toxicity), and lactation.

Adverse effects

Lidocaine as Antiarrhythmic-Systemic Administration

  • CNS: Dizziness/lightheadedness, fatigue, drowsiness, unconsciousness, tremors, twitching, vision changes, may progress to seizures, convulsions
  • GI: Nausea, vomiting
  • CV: Cardiac arrhythmias, cardiac arrest, vasodilation, hypotension
  • Respiratory: Respiratory depression and arrest
  • Hypersensitivity: Rash, anaphylactoid reactions
  • Other: Malignant hyperthermia

Lidocaine as Injectable Local Anesthetic for Epidural or Caudal Anesthesia

  • CNS: Headache, backache, septic meningitis, persistent sensory, motor, or autonomic deficit of lower spinal segments, sometimes with incomplete recovery
  • CV: Hypotension due to sympathetic block
  • GU: Urinary retention, urinary or fecal incontinence

Lidocaine as Topical Local Anesthetic

  • Dermatologic: Contact dermatitis, urticaria, cutaneous lesions
  • Hypersensitivity: Anaphylactoid reactions
  • Local: Burning, stinging, tenderness, swelling, tissue irritation, tissue sloughing and necrosis
  • Other: Methemoglobinemia, seizures

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