Drug Card: Lidocaine

Medication Name: Lidocaine

  • Generic Name: Lidocaine

  • Trade Name(s): Xylocaine

Drug Classification: Antiarrhythmic / Local Anesthetic

Description:
Lidocaine is primarily used to treat ventricular arrhythmias and as a local anesthetic. It acts quickly and has a wide range of applications, including in emergency settings for cardiac arrest.

Mechanism of Action:
Lidocaine works by blocking sodium channels in the cardiac cell membrane, which decreases the rate of depolarization and increases the threshold for depolarization, stabilizing the cardiac cell membrane.

Pharmacokinetics:

  • Absorption: Rapidly absorbed when given IV; slower absorption via other routes.

  • Distribution: Widely distributed throughout the body; crosses the blood-brain barrier.

  • Metabolism: Metabolized primarily in the liver.

  • Excretion: Excreted in urine as metabolites; half-life is about 1.5 to 2 hours.

Indications/Field Use:

  • Ventricular fibrillation (VF)

  • Ventricular tachycardia (VT)

  • Local anesthesia in minor surgical procedures

Contraindications:

  • Hypersensitivity to lidocaine

  • Severe heart block (without a pacemaker)

Side Effects/Adverse Reactions:

  • Drowsiness

  • Confusion

  • Hypotension

  • Cardiac arrest (rare)

Dose:

  • Ventricular Fibrillation/Pulseless VT: 1 to 1.5 mg/kg IV bolus; may repeat with 0.5 to 0.75 mg/kg every 5-10 minutes (max 3 mg/kg).

  • Maintenance Infusion: 1-4 mg/min.

Precautions:

  • Monitor for signs of toxicity (CNS effects).

  • Adjust doses in patients with liver disease.

Drug-Drug Interactions:

  • Increased risk of CNS toxicity with other CNS depressants (e.g., benzodiazepines).

  • Caution with antiarrhythmics (may increase lidocaine levels).