Pharmacology - Arrhythmias Part 3 Flashcards
sotalol MOA
potassium channel blocker (class 3) AND has beta blocking effects (class 2_
can sotalol be used in pediatric arrhythmias
yes
true or false
sotalol undergoes extensive metabolism
FALSE
no metabolism and is excreted unchanged
like amiodarone, _____ decreases the threshold for cardiac defibrillation
sotalol
route sotalol
oral or IV
true or false
sotalol undergoes extensive metabolism
FALSE - no metabolism and is excreted unchanged in the urine
true or false
sotaolol does not have respiratory AE
FALSE - bronchospasm bc non selective beta blocker
does dofetilide show reverse use dependence?
what does this show about torsa risk?
yes - increased risk
cimetidine + dofetilide interaction
increased half life of dofetilide
bc dofetilide is renally excreted by cation secretion mechanism
cimetidine inhibits this
verapamil + dofetilide
increased dofetlidie levels
(verapamil is CYP3A4 inhibitor)
true or false
dofetlidie needs dose adjustment in renal issues
true
the risk of torsa from dofetilide becomes higher when?
when given with potassium depleting diuretics – hypokalemia = incrased risk of torsa
ibutilide route of administration
iv
what calcium channel blockers are used in arrhythmia
ONLY diltiazem and verapamil - not the dihydropyridines
true or false
the non DHP calcium channel blockers block both activated AND inactivated L type calcium channels
true
4 miscellaneous agents that are antiarrhythmics
adenosine
ranolazine
ivabradine
magnesium
What receptor does adenosine bind to? does it activate or block the receptor? where are these receptors located?
activates Gi-coupled adenosine receptors in the heart
true or false
adenosine decreases the intracellular effect of cAMP
true
true or false
adenosine speeds up heart rate and AV conduction
FALSE - slows
adenosine activates what current? inhibit what current?
activates inward K current
inhibits calcium current
administration of adenosine
half life?
IV bolus ONLY
half life is seconds - reapidly deaminated
true or false
adenosine is considered a safer antiarrhythmic
true - it’s rapidly cleared and doesnt stay in the body for a long time like amiodarone
some AE of adenosine
skip heart beats (transient assystole), rare a fib and bronchospasm
true or false
adenosine is not given orally
true - IV bolus only
adenosine + dipyridamole
potentiation
caffeine/theophylline + adenosine
antagonized effects
2 uses for magnesium
treatment for ALL patients with torsa - even if mg levels are normal
only if hypomagnesia — patients with digoxin-induced arrhythmias
magnesium has ant ____ effects and anti ____ effects
anti-ischemic and anti-arrhythmic
true or false
magnesium increases oxygen demand
false - decreases
true or false
ranolazine is only an antiarrhytnic
false - also anti anginal
ranolazine is a ____ modulator
what does it block
metabolic
blocks the LATE sodium current - different kind of block than the sodium channel blockers
ranolazine inhibits the late ____ sodium current in the heart muscle
inward
physiologic effect of ranolazine
decreased oxygen requirements, decreased cell swelling (edema)
ranolazine + cyclosporine
any other DDI concerns?
absorption of ranolazine will be increased bc cyclosporine will inhibit pgp
all 3A4 interactions are a concern
is renal function a consideration for ranolazine
yes
true or false
ranolazine does not cause torsa
true - causes QT prolongation but no torsa
ivabradine MOA
selective blocker of HCN ion channels
(hyperpolarization-activated HCN channels)
regulates SA node to decrease HR and O2 demand - antiarrhytmic AND antianginal
what does HCN stand for in “hyperpolarization-activated HCN ion channels”
hyperpolarization-activated cyclic nucleotide gated channels
atropine effects on heart
increases the heart rate in bradycardia patients
true or false
atropine is able to increase the heart rate through decreasing activity of the vagus nerve
true
