Antiarrhythmics

Question 1

What Channel blockers are Class IA, IB,IC?

Answer 1

Na Channel blockers

Question 2

What drugs are Class IA Na channel blockers?

Answer 2

Disopyramide
Procainamide

Question 3

What drugs are Class IB Na channel blockers?

Answer 3

Lidocaine
Mexiletine

Question 4

What drugs are Class IC Na channel blockers?

Answer 4

Flecainide
Propafenone

Question 5

What blocking agent is B1?

Answer 5

Class II

Question 6

What drugs are Class II B1 blocking agents?

Answer 6

Metoprolol
Acebutolol
Esmolol
Propranolol

Question 7

What channel blockers are Class III?

Answer 7

K channel blockers

Question 8

What drugs are Class III K channel blockers?

Answer 8

Amiodarone
Sotalol
Dofetilide
Ibutolode

Question 9

What channel blockers are class IV?

Answer 9

Ca channel blockers

Question 10

What are the drugs in Class IV Ca channel blockers?

Answer 10

Verapamil
Diltiazem

Question 11

Adenosine Digitalis drug?

Answer 11

Digoxin

Question 12

Parasympathetic (vagal) outflow goes to SA node which results in _____ heart rate

Answer 12

decrease heart rate

Question 13

Sympathetic outflow goes to SA and AV nodes which results in _____ heart rate

Answer 13

increases heart rate

Question 14

Sympathetic nerves activate _______ receptors in the heart

Answer 14

B1 adrenergic receptors

Question 15

Slow action potential occurs in _____ and _______ ?

Answer 15

SA and AV nodes (pacemakers) (right)

Question 16

Fast action potential occur in ________ and _______?

Answer 16

Purkinje fibers and muscle fibers (left)

Question 17

Class IA: Na channel blockers therapeutic uses?

Answer 17

-Most effective with atrial arrhythmias
- particularly effective with ectopic foci and reentrant arrhythmias
- are myocardial depressants and reduce automaticity, responsiveness, and increase refractoriness (increasing ERP)

Question 18

Nifedipine use

Answer 18

Selectively block L-type Ca2+ channels in blood vessels in heart & peripheral vasculature

Used for HTN because they decreased TPR & arterial pressure w/o changing contractility or HR

Question 19

Verapramil
Use:
Side effects

Answer 19

May produce cardiac depression & AV block (when put with. BB)
CI in BB use
Used to tx HTN, chronic angina, & arrhythmias

Hyperprolactinemia – affect w/ dopamine
Constipation in 10% of pts

Question 20

Dihydropyridines “-prils” overall and use

that does it decrease and through what?
Is There change to the heart rate?

Affective in who?
What is the preferred combo?
Safe in pregnancy?

Answer 20

-Decreases BP through arteriolar smooth muscle relaxation & decreasing PVR
- No – mild HR changes due to working in the vasculature

Uses:
More effective in A.A or low-renin HTN
Preferred medication for elderly pts
ACEi + amlodipine > ACEi + HCTZ in reducing CV events
Safe in pregnancy

Question 21

Nifedipine

Decrease or increase peripherally?
For what treatments is it used for?

Answer 21

L-type Ca2+ channels = target in vascular smooth muscle
Decrease BP peripherally
Increases excretion of Na+ due to acting on renal afferent arterioles
Decreases O2 consumption and increases supply through working on the coronary arteries
Tx of HTN & chronic angina

ADEs: Pretibial edema, nausea, flushing, dizziness, gingival hyperplasia
Give a slow-release preparation to avoid reflex tachycardia

Question 22

A-1 blockers

MOA?
Effect?
Side effects?

Answer 22

MOA – blocks a-1 receptors in arteries & veins
Effects – Decreases TPR & BP

Side effect: Prazosin – 1st-dose hypotension. Give at bedtime. Only worried about patients w/ orthostatic hypotension.

Doxazosin & Terazosin are used in urinary s/s of BPH by relaxing bladder/prostate muscles