3.3 Pharmcokinetics and dynamics of cardiac drugs

Question 1

what are the 4 classes of anti arrhythmic drugs? and give an example of each

Answer 1

Class 1: Na channel blocker
1a. Quinidine, 1b. Lidocaine, 1c. Flecainide

Class 2: beta blockers
Propranolol, metoprolol

Class 3: inhibitors of K channels
Amiodarone

Class 4: Calcium channel blockers
Verapamil, Nifedipine

Question 2

What do class 1 AA drugs do?

Answer 2

Reduce phase 0 slope and peak of action potential by inhibiting Na

Question 3

What do class 2 drugs do?

Answer 3

Block the beta 1 receptors in the heart – block sympathetic activity (decrease slope of phase 4)

Question 4

What do class 3 drugs do?

Answer 4

Prolonged repolarization (phase 3)

Question 5

What do class 4 drugs do?

Answer 5

Slows AP upstroke and conduction velocity in nodes

Question 6

What kind of tropism do each drug class have?

Answer 6

1. -ve chronotrope
2. -ve chrono and inotrope
3. -ve chronotrope
4. -ve chrono and inotrope

Question 7

what are the positive inotropic drugs used for heart failure?

Answer 7

Cardiac glycosides
Phosphdiesterace inhibitors
beta agonists

Question 8

What re the drugs acting on non cardiac targets for heart failure?

Answer 8

diuretics
ACE inhibitors
Beta blockers