Anti-arrhythmic drugs

Question 1

What are class I anti-arrhythmics?

Answer 1

Sodium channel blockers

1A moderate, quinidine
1B weak, lidocaine
1C strong, flecainide

Question 2

What are the class II drugs?

Answer 2

Beta blockers

First line for atrial fibrillation

Question 3

What are the class III drugs?

Answer 3

Potassium channel blockers

amiodarone, bretylium, sotalol

Increase ap duration

Question 4

Amiodarone uses?

Answer 4

VT and ocassionally SVT

Many drug interactions

striking side effects

Question 5

Class IV ?

Answer 5

Calcium channel blockers

verapamil, diltiazem

Question 6

Class V?

Answer 6

Other

Digoxin (cardiac glycoside)
-increases vagal tone, slows conduction
-reduces refractory period
-positively ionotropic
-used in AF, atrial flutter, SVT, heart failure

Adenosine

Question 7

What can digoxin toxicity lead to?

Answer 7

Nausea and vomiting
Xanthopsia
Bradycardia
Tachycardia
Arrhythmias: VT and VF

Question 8

How do you treat digoxin toxicity?

Answer 8

Stop digoxin: but long half life
If levels very high and risk of significant arrhythmia: Give Digibind
Digibind
Digoxin immune antibody
Binds with digoxin, forming complex molecules
Excreted in urine

Digoxin toxicity is more serious if potassium levels are low

Question 9

Adenosine?

Answer 9

Converts SVT to sinus rhythm

Question 10

What drugs increase warfarin activity?

Answer 10

aspirin, sulfonamides, cimetidine, erythromycin, antibiotics

Question 11

What drugs decrease warfarin activity?

Answer 11

barbiturates, phenytoin, vit K, cholestyramine