class 1b

Question 1

lidocaine

Answer 1

Action: Block activated and deactivated Na+ channels/shortens Repolarization time; decreases phase 0 and AP duration
Use: acute suppression of ventricular arrhythmias esp. after MI/cardioversion; digitalis-induced arrhythmias
Side Effects: CNS effects
Contraindications: B blockers decrease clearance of lidocaine so you should monitor lidocaine levels
Notes: Class IB act preferentially on depolarized, arrhythmic tissue

Question 2

phenytoin

Answer 2

Action: Block activated and deactivated Na+ channels/shortens Repolarization time; decreases phase 0 and AP duration
Use:acute suppression of ventricular arrhythmias esp. after MI/cardioversion; digitalis-induced arrhythmias
Side Effects: CNS effects

Question 3

mexiletine

Answer 3

Action: Block activated and deactivated Na+ channels/shortens Repolarization time; decreases phase 0 and AP duration
Use: acute suppression of ventricular arrhythmias esp. after MI/cardioversion; digitalis-induced arrhythmias
Side Effects: CNS effects

Question 4

tocaninide

Answer 4

Action: Block activated and deactivated Na+ channels/shortens Repolarization time; decreases phase 0 and AP duration
Use: acute suppression of ventricular arrhythmias esp. after MI/cardioversion; digitalis-induced arrhythmias
Side Effects: CNS effects