Arrthymia And Drugs

Question 1

What’s are the 5 classes of anti-arrhythmia drugs?

Answer 1

Class 1: VG Na+ blockers(affect the conduction thru the myocyte)
Class 2: Anti-sympathetic/Beta blockers(affect nodal AP,Ca2+ is decreased)
Class 3:VG K+ blockers(affect both APs)
Class 4:VG Ca2+ blockers(affect both nodal n Cardiac AP)
Others:Digoxin,Adenosine…

Question 2

What are the diff forms of class 1 anti-arrhythmic drugs?

Answer 2

C-A-B
Arranged according to strength of block
Affect phase O
Prolong refractory period,depolarization and repolarisation

Question 3

Name class 1a drug and MOA

Answer 3

DISOPYRAMIDE
*has anticholinergic effect
*used for both atrial and ventricular tachycardia
*inhibits both Na+ & K+, Purkinje channels

Question 4

Name class 1b drugs and MOA

Answer 4

MEXILETINE—oral
LIDOCAINE—IV administration also local an anaesthetic
* weakest block
Only for ventricular tachycardia NOT ATRIAL

Question 5

Name class 1c drugs and MOA

Answer 5

FLECAINIDE
PROPAFENONE.. beta blocker too
* used for both atrial and ventricular tachycardia

Question 6

Name a class 2 antiarrhythmic drug and MOA

Answer 6

SOTALOL
Is a beta blocker hence also lowering Ca++ levels
Asthma contraindication
Has class 3 effects too

Question 7

Name a class 3 drug and MOA

Answer 7

AMIODARONE
Good for treatment of Wolfe Parkinson-white syndrome
K+ channel blocker
Has class la,2,4effects

Question 8

Name a class 4 drug and MOA

Answer 8

VERAPAMIL
DILTIAZEM

These are also antihypertensives
Calcium channel blockers esp L-type

Question 9

Name the 2 miscellaneous drugs used to treat arrhythmia

Answer 9

1.DIGOXIN….cardiac glycosides, Na/K inhibitor
2.ADENOSINE… IV admin,short acting & strong vasodilator

Question 10

Which drug is used to treat bradycardia and its MOA

Answer 10

IV ATROPINE
mAChR antagonist
Pacemakers usually used to treat the condition hence not many developed drugs