Sodium Channel Blockers - Nordgren

Question 1

Which kind of Na channel blocking drugs decrease AP?

Answer 1

Subgroup 1B: Lidocaine, Mexilitine, Tocainide

“Buy Lidia’s Mexican Tacos”

Question 2

Subgroup C of the Na channel blockers.
What are the drugs?
How do they affect AP duration?

Answer 2

Flecainide
Propafenone
(Cats with FLEas get PROPs)

Subgroup C is the only group that DOES NOT affect AP duration.

Question 3

What are the subgroup A Na channel blockers?

How do they affect AP duration?

Answer 3

Subgroup 1A:
Quinidine
Disopyramide
Procainamide

“The queen of disco-pyramid proclaims!”

Question 4

Which Na channel blocker subgroup is best for post-myocardial infarction?

Answer 4

1B = Best for post-MI
(also good for acute ventricular arrhythmia)

Lidocaine
Mexitiline
Tocainamide

Question 5

What are subgroup C Na-blockers used for?

Answer 5

Ventricular tachycardias that progress to V-Fib and intractable SupraV Tachycardia

Question 6

Name the beta blockers:

How do they work?

Answer 6

Beta Blockers:

• Propanolol
• Acebutolol
• Esmolol
• Sotalol

Block SNS effect in heart.
(Decrease SA/AV node activity by decreasing cAMP -> decreasing Ca currents)

Question 7

Clinical use of beta blockers?

Answer 7

V-Tach, SupraV Tach, slowing ventricular rate during A-fib and A-flutter

Question 8

Toxicity for beta blockers?

Answer 8

Impotence, asthma exacerbation, sedation, etc.

Question 9

Name the K-blocker drugs:

When do you use them?

Answer 9

Amiodarone
Dofetilide
Ibutilide
Sotalol

Use when all else fails!

Question 10

Class 1 drugs all create this ion problem:

Answer 10

Hyperkalemia

Question 11

Mechanism by which class 4 Ca channel blockers work?

Answer 11

Block v-gated Ca channels to reduce muscle contractility

• Decreases conduction velocity
• increase ERP
• Increase PR interval

Question 12

What are the Ca-clocking drugs?

Answer 12

Verapamil, Dilitiazem,

Nifedipine, Amlodipine

Question 13

What do you use Ca blockers for?

Answer 13

Prevention of nodal arrhythmias

Question 14

Toxicity of Ca blockers?

Answer 14

Cardiac depression, AV block, peripheral edema, flushing, dizziness, constipation

Question 15

Toxicity of Class 3’s

• Amiodarone:
• Solatol:
• Ibutilide:

Answer 15

• Amiodarone: class 1,2,3,4 effects, pulmonary fibrosis, heptotoxicity, hypothyroid
• Solatol: torsades de pointes, excess beta-blcoking
• Ibutilide: torsades

Question 16

Describe the differences in selectivity between propanolol, acebutolol, esmolol, and solatol:

Answer 16

propanolol: non-selective
acebutolol: Cardio-selective beta-1 blocker
esmolol: beta-1 selective
solatol: non-selective beta-blocker

Question 17

Which beta blocker is best for patients with asthma?

Answer 17

Acebutolol: because it is a cardio-selective beta-blocker, so it won’t cause bronchospasm