Lidocaine (Xylocaine)

Question 1

Drug Classification

Answer 1

Antidysrhythmic

Question 2

Mechanism of action

Answer 2

Class IB antiarrhythmic/Na+ channel blocker -> decreases slope and amplitude of phase 0 depolarization for non-pacemaker action potential

Question 3

Pharmacokinetics

Answer 3

Onset of Action- <3 minutes
Peak Effects- 5-7 minutes
Duration of Effects- 10-20 minutes
Half-Life- 1.5-2 hours

Question 4

Indications/Field Use

Answer 4

• VF, VT

- Anesthetic effect for IO use

Question 5

Contraindications

Answer 5

• 2nd degree type II, 3rd degree heart block

- bradycardia

Question 6

Side Effects/Adverse Reactions

Answer 6

Flushing, sweating, itching, rash, bradycardia, drowsiness, seizures, confusion, hypotension, N&V, heart block

Question 7

Dose

Answer 7

Adult:
VF/Pulseless VT- 1st Dose- 1-1.5mg/kg IV/IO
2nd dose- 0.5-0.75mg/kg IV/IO, then 1-4mg/min maintenance
VT with pulse- 0.5-1.5 mg/kg IV/IO, then 1-4mg/min maintainance

Pedi:
1mg/kg IVP, repeat dose after 15min PRN, maintainance 20-50mcg/mg/min

Question 8

Precautions

Answer 8

Pt. 70+ years or known hepatic failure- reduce maintainance dose by half

Question 9

Drug-drug interaction

Answer 9

Potentiates procainamide, phenytoin, quinidine and beta blockers