AntiarrhythmicsFC Flashcards
The most common causes of an arrhythmia are…..
coronary heart disease, heart valve disorders, heart failure, and damage from heart attack
QT prolongation is a marker for ventricular tachyarrhythmias, including torsades.
good to know
what are 2 factors to consider when looking at drugs that can prolong the QT interval?
dose and duration
what are some agents that have additive QT prolongation?
Class 1a and Class III antiarrhythmics (amiodarone, disopyramide, dronaderone, pocainamide, quinidine, sotalol)
abx - FQNs, macrolides,
azole antifungals
anticancer agents
protease inhibitors
SSRIs / SNRIs
antiemetics - ondansetron, droperidol
antipyschotics
Rate control vs rhythm control?
studies show that ventricular RATE control is as effective as rhytum control with cardioversion and antiarrhytimic drugs
What drugs are used for rate control in pts with afib?
BB, non DHP CCBs (V&D) and digoxin
What are the Class 1 antiarrhythmics?
1a - Double Quarter Pounder = Disopyramide, Quinidine, Procainamide
2a - Mayo Lettuce - Mexiletine, Lidocaine
3a - Fries Please - Flecainide , Popafenone
what are the Class II antiarrhythmics?
BB - esmolol, propranolol
What are the class III antiarrhythmics?
amiodarone, Dofetilide, dronaderone, Ibutilide, sotalol
What are the class IV antiarrhythmics?
Verapamil, Diltiazem
What is the MOA of the Class IAs?
block Na channels, decrease conduction velocity, increase refractory period, decrease automaticity
What dietary considerations should be made when taking quinidine?
Avoid changes in Na intake. decreased Na intake can increase quinidine serum conc.
-take with food or milk to dec GI upset
What is the BBW with quinidine?
may increase mortality in treatment of Afib/A.flutter
What is the major side effects of quinidine?
diarrhea, cramping, cincohnism (tinnitus, eye issues etc), N, V
What 2 Class 1A’s must be taken on an empty stomach?
procaiamide and disopyramide
what are the BBW’s on procainamide?
fatal blood dyscrasias,
positive ANA test leading to drug induced lupus like syndrome
what is the name of the active metabolite of procainamide ?
METABOLIZED by acetylation to N-acetylprocainamide (NAPA), which makes it active!! KNOW
SE procainamide
hypotension, n, V, D, Lupus like syndrome, qt prolongation, and agranulocytosis
What major side effects of disopyramide?
anticholinergic effects (can’t see ,spit, pee, poop)
Quinidine is a major substrate of what CYP?
3A4
What is the MOA of class IB antiarrythmics?
block Na channels, decrease refractory period, decrease automaticity
what is the use of class 1 b antiarrythmics
only used for ventricular arrhythmiaxs
Lidocaine is a substrate of what 2 CYP ?
3A4 and 2D6
What is the MOA of Class IC antiarrythmics?
block Na channels, significantly decrease conduction velocity, decrease automaticity
Not used much
What are the Class II antiarrythmics?
esmolol (Brevibloc) / propranolol (Inderal)
What is the MOA of the Class III antiarrythmics?
blocks mainly K channels, no change on conduction velocity, significant increase in refractory period
what are the class 2 antiarrhytmics?
esmolol and propranolol
what is the difference between esomolon and propranolol?
esmolol is beta 1 selective (just affects the heart) and propranolol is beta non selective
what is the use of class 2 antiarrhythmics?
the use is for ventricular arrhythimias
What are they?
amiodarone (cordorone)
Dronaderone (Multaq)
sotalol (Betapace)
ibutilide (Corvert)
dofetilide (Tikosyn)
pacerone
amiodarone
nexterone
amiodarone
cordorone
amiodarone
multaq
dronaderone
betapace
sotalol
corvert
ibutilide
tikosyn
dofetilide
Which class III has a REMS?
Tikosyn (dofetilide)- initial dose HAS to be given in a hospital and adjusted based on QT and renal function
What is unique about administration of IV amiodarone?
infusions lasting longer than 2 hours must be administered in non-PVC container
What are the 4 BBWs for amiodarone? KNOW
- pts should be hospitilized when therapy is initiated
- lung damage may occur w/out symptoms
- liver toxicity
- exacerbation of arrhythmias - more difficult to reverse
what are some side effects of amiodarone? (theres a lot)
hypotension (IV), bradycardia, increase LFTs, corneal microdeposits, optic neuritis, pulmonary fibrosis, photosensitivity, blue skin, insomnia
what is important about the dosing /dosage forms of sotalol?
Betapace should not be substituted for Betapace AF
What is the BBW for sotalol (Betapace)
initiation and dosage increase should be done in a hospital
What is the BBW for dofetilide?
Tikosyn must be initiated or reinitiated in a setting with continuous ECG monitoring for 3 days or 12 hours after cardioversion
What medications must have a dose reduction of 30-50% while taking amiodarone?
digoxin, warfarin, quinidine, procainamide
also, lower doses of Ator, Lova, Simvastatin
DDIs for amiodarone?
Amiodarone is an inhibitor of CYP 2C9, 2D6, 3A4 and p-glycoprotein
When might CCB’s be preferred over BB’s in pts with arrythmias?
if the pt has asthma or COPD
What is the therapeutic lab value for digoxin in afib?
0.8-2.0
What is the dose adjustment from oral to IV digoxin?
decrease dose by 20-25% when going from oral to IV
what are signs of digoxin toxicity?
N/V, loss of appetite, bradycardia
blurred or yellow vision, confusion
digoxin can accumulate with _____
renal insufficiency
What electrolyte imbalances can increase chance of digoxin toxicity?
hypokalemia, Hypercalcemia
Multaq - generic name and class, indication
dronedarone - Class III
only indicated for maintenance of sinus rhythm. CI IN persistant afib
What is the normal lab value for K?
3.5-5 meq/L
Which of the following is not a side effect of amiodarone? skin discoloration, corneal deposits, lung damage, taste perversion, hypothyroidism
taste perversion
greatest risk of qt prolongation
class 1a and class III
how is the classification determined for van gough class 1
a= INTERMEDIATE
b- SHORT
C. long
NOTICE NOT in right order.
dronadarone bbw
- class IV heart failure
- pts w/ permenant AFIB.
Adenosine
works by ACTIVATING A1 receptors- causes a transiet BLOCK in the AV node.
adenosine ADR
ADR: headache, flushing, chest pain
half life of amiodarone is abt
60 days
Digoxin- MOA
helps to control RATE. digoxin works on AV node conduction. DEcreases resting RATE.
amiodarone good for
pts w/ structural heart dz, decompensated heart failure. BUT 1c- is BAD CI in these cases and 1a- is meah
