Anti-arrhythmic drugs

Question 1

2 class Ic drugs? MOA?

Answer 1

flecainide
propafenone
MOA: block open Na2+ channels

Question 2

predicted actions: markedly slows phase 0 depolarization

uses: rhythm control, paroxysmal a. fib, SVT, ventricular arrhythmias, Wolff-Parkinson-White Syndrome

Answer 2

class Ic drugs: flecainide, propafenone

Question 3

SEs: proarrhythmia, QT prolongation

increases digoxin concentration, increased activity when paired w/haloperidol, cimetidine, fluoxetine

Answer 3

flecainide, a class Ic drug

Question 4

SEs: proarrhythmia in pts w/ischemic heart disease, QT prolongation, 1st or 2nd degree AVN block metallic taste, dizziness
may increase digoxin concentration, decreases warfarin metabolism, C/I in HF NYHA III-IV, liver dz, valvular dz, CAD, or V. tach

Answer 4

propafenone

Question 5

class II drug? MOA?

Answer 5

propranolol

MOA: blocks catecholamines, blocks at the AV node

Question 6

predicted actions: decrease slope of phase 4 depol, prolong repol in AV node= blocks re-entry
uses: rate control, tachyarrhythmia, SV arrhythmias, a. flutter, ventricular arrhythmias
SEs: bradycardia, hypotension, LV failure, AVN block, bronchospasm
C/I w/ sick sinus syndrome, bradycardia or heart block

Answer 6

propranolol, a class II anti-arrhythmic

Question 7

5 class III anti-arrhythmics?

Answer 7

amiodarone
sotalol
ibutilide
dofetilide
dronedarone

Question 8

MOA of class III anti-arrhythmics?

Answer 8

block lKr, K+ channel block

Question 9

distinguishing characteristics: T1/2 of 26-107 days
predicted actions: prolong phase 3 depolarization w/o altering phase 0
uses: rhythm control, SV & ventricular arrhythimas

Answer 9

amiodarine, a class III anti-arrhythmic

Question 10

SEs: corneal microdeposits, peripheral neuropathy, pulmonary fibrosis, disturbed thyroid fxn, photosensitivity w/blue/gray discoloration of skin, may precipitate heart failure

Answer 10

amiodarine, a class III anti-arrhythmic

Question 11

predicted actions: prolong phase 3 depol w/o altering phase 0
uses: Wolf-Parkinson-White Syndrome, rhythm control, ventricular arrhythmias, maintenance of a. flutter
SEs: non-selective beta blockade, torsades

Answer 11

sotalol, a class III anti-arrhythmic

Question 12

C/I w/idoine hypersensitivity, hyperthyroidism, 3rd degree AV heart block, D/I with warfarin (reduce dose by 25%-50%) and re-check INR, with concurrent digoxin use reduce dose by 50%, with concurrent statin use the max dose is 20 mg

Answer 12

amiodarone, a class III anti-arrhythmic

Question 13

3 class IV anti-arrhythmics? MOA?

Answer 13

verapamil (diphenyl alkamine)
diltiazem (benzothiazepine)
amlodipine (dihydropyridine)
MOA: Ca2+ channel blockers

Question 14

MOA: blocks L-type Ca2+ channels, decreases AV node conduction & increases refractory period

Answer 14

class IV anti-arrhythmics, CCBs, diltiazem & verapamil

Question 15

distinguishing characteristics: similar to class II but doesn’t block adrenergic system
predicted actions: slows phase 4 depol & slows conduction particularly at the AV node
uses: rate control, prevent recurrence of PSVT, control ventricular rate in a.fib, HTN, angina
SEs: negative inotropic, AVN block, sinus arrest, peripheral vasodilation, constipation, dizziness, flushing, H/A, hypotension, gingival hyperplasia

Answer 15

class IV anti-arrhythmics, CCBs

Question 16

3 “other” anti-arrhythmics?

Answer 16

digoxin
adenosine
atropine

Question 17

MOA: inhibits Na/K ATPase in myocardium

Answer 17

digoxin

Question 18

MOA: acts on certain receptors to decrease adenyl cyclase to decrease cAMP

Answer 18

adenosine

Question 19

MOA: competitive inhibitor of muscarinic acetylcholine receptors

Answer 19

atropine

Question 20

distinguishing characteristics: decreases membrane Na+ gradient, decreases Na-Ca exchange, increases intracellular Ca2+
uses: rate control, a. fib, a. flutter w/RVR, heart failure
SEs: bradycardia, partial or complete heart block, GI, drowsiness, fatigue, visual disturbances
what is it’s antidote?

Answer 20

digoxin

antidote is digibind

Question 21

distinguishing characteristics: increases K+ efflux= cell hyperpolarization= transient heart block of AV node
uses: AV re-entrant tachycardia, AV nodal re-rentrant tachycardia, acute paroxysmal supraventricular tachycardias
SEs: transient hypotension & chest pn
recommended as initial drug of choice for PSVT

Answer 21

adenosine

Question 22

use: bradycardia
SEs: blurry vision, dry mouth, tachycardia
ssxs of overdose?
antidote?

Answer 22

atropine
ssxs of overdose: dry as a bone, red as a beet, mad as a hatter, blind as a bat
antidote: neostigmine