anti-arrhythmic drugs

Question 1

Which channels do class 1a,b,c block

Answer 1

Na channels
Phase 0

Question 2

Name a class 1A drug

Answer 2

Procainamide

Question 3

Procainamide MOA

Answer 3

1. reduces rate of Phase 0 rise
2. increases effective refactory period ERP

Question 4

Name a class 1B drug

Answer 4

Lidocaine

Question 5

Lidocainem MOA

Answer 5

1. reduces rate of phase 0 rise
2. shortens phase 3 repolarisation
3. reduce APD
4. no change to ERP

Question 6

Name a class 1C drug

Answer 6

Flecainide

Question 7

Flecainide MOA

Answer 7

1. reduces rate of phase 0 rise
2. shortens phase 3 repolarisation
3. no change to ADP and ERP

Question 8

What are class 2 drugs

Answer 8

beta blockers
1. metoprolol
2. propranolol

Question 9

beta blockers MOA

Answer 9

1. reduce phase 4 depolarisation
2. reduce HR and contractility
3. no change in erp

Question 10

beta blockers CVS clinical uses

Answer 10

1. tachycardia
2. atrial fibrillation

Question 11

What channel does class 3 block

Answer 11

potassium channels

Question 12

Name a class 3 drug

Answer 12

amiodarone

Question 13

Amiodarone MOA

Answer 13

1. prolongs phase 3 repolarisation
2. increases ERP and APD

Question 14

Amiodarone clinical uses

Answer 14

1. normal sinus rhythm in patients with atrial fibrillation
2. reentrant ventricular tachycardia

Question 15

Amidarone adverse effects

Answer 15

bradycardia and heart block

Question 16

What channels to class 4 block

Answer 16

calcium channel blockers
(non-DHP channel bloclers have higher selectivity for AV nodal calcium channels)

Question 17

Name 2 drugs in class 4

Answer 17

verapamil and diltiazem

Question 18

Verapamil and diltiazem MOA

Answer 18

increases ADP and ERP

Question 19

Verapamil clinical uses

Answer 19

1. supraventricular tachycardia
2. hypertension (not the best)
3. angina

Question 20

Verapamil adverse effects

Answer 20

hypotension
contraindicated in patients with preecisting depressed cardiac fx

Question 21

Adenosine MOA

Answer 21

• supress AV nodal conducrion
• increase AV nodal refactory period
• stimulates cardiac K+ channel
• inhibits calcium current
• half life less than 10s

Question 22

Adenosine clinical use

Answer 22

supraventricular tachycardia

Question 23

adenosine adverse effects

Answer 23

1. flushing
2. shortness of breath
3. chest burning
4. induction of AV block/ AF
   5.headache
5. hypotension