Cardiovascular Drugs Flashcards
What is arrhythmia?
alteration in normal impulse pathway
Name major cause of sudden cardiac death.
ventricular fibrillation
what is cardioversion?
global depolarization of heart to reset heart beat. Can be achieved via defibrillation
automatic defibrillators can be implanted
radiofrequency ablation accomplishes what?
the removal of ectopic foci - points that induce abnormal electrical signals in the heart
Do antiarrhhythmic drugs affect ectopic or normal foci more?
ectopic
What class of drug is quinidine?
Treats which arrhythmias?
range of effectiveness?
SEs?
class Ia sodium channel blocker
effective in treating all arrhythmias
depresses all muscle function
SEs:
- GI upset
- Nausea
- Anorexia
- CNS: tinnitus, altered color vision
Which class of drug is Procainamide?
Treats which arrhythmias?
analog of what?
Does it enter CNS?
Notable SE?
class: Ia sodium channel blocker
Treats: all arrhythmia
analog of Procaine
DOES NOT enter CNS
SE: in slow acetylators, lupus-like syndrome
Disopyramide is what class of drug?
Effects?
used to treat which type of arrhythmias?
class: sodium channel blocker
strong anti-vagal effects aka anti-muscarinic effect (opposite of DUMBBELS)
treats: ventricular arrythmias
Lidocaine is what class of drug?
Lidocaine is the DOC for what?
Does Lidocaine enter the CNS?
SEs?
class Ib sodium channel blocker
DOC for ventricular tacchycardia
less likely to cause arrhythmias
Yes, it does enter CNS
CNS SEs:
- tremors
- seizures
Mexiletine is similar to what other sodium channel blocker?
Lidocaine and also is a class Ib sodium channel blocker
Name the 5 sodium channel blockers used to treat arrythmias
Procainamide - all arrhythmias
quinidine - all arrhythmias
disopyramide - ventricular arrhythmias
lidocaine - ventricular tachycardia
mexiletine - not specified
Name 3 beta blockers used to treat arrhythmia and additional characteristics of each.
MOA?
SEs?
Propanolol: also affects beta2, decreases pacemaker firing rate
Osmolol: rapid onset
Metoprolol: more selective, less beta2 effect
MOA: block beta-1 receptors in heart - effectively slows HR
SEs:
-hypotension
if beta 2 affect: asthma concerns
What are the K+ channel blockers used?
atrial fibrillation
name 3 potassium channel blockers used for atrial fibrillation and characteristics / SEs of each
Sotalol: beta blocker that also blocks potassium channels
Amiodarone: acts like all 4 antiarrhythmic drug classes -most effective: DOC for cardiac arrest -contains iodine SEs: -potentially fatal pulmonary fibrosis -liver damage -corneal deposits --> optic neuritis -skin deposits --> blue skin coloration (iodine) -GI upset
Dronedarone:
- analog of amiodarone
- fewer SEs, less efficacy
Name 3 calcium channel blockers used to treat arrhythmia.
What is their effect on cardiac cells?
For which arrhythmia type are they useful?
Diltrazem
nifedipine
verapamil
increase refractory period
NOT useful for ventricular arrhythmia
How does adenoside work?
What is its effect?
For what is it used?
binds adenosine receptor -> slows AV node
serves as coronary vasodilator
used for atrial tachycardia and disappears quickly
how is angina treated?
increasing blood flow to heart or by decreasing O2 demand
nitrates - nitroglycerin (GTN)
-rapid dilation of all blood vessels
exercise - increase collateral circulation
isosorbide dinitrate - slow release nitrate formulation (oral admin b/c slow release off sets first pass of GTN)
beta blockers
calcium channel blockers
For what is nitroglycerin used?
MOA?
Side Effects?
angina, life threatening hypertension
GTN -> NO -> activates guanylate cyclase -> cGMP (vasodilator)
SEs:
- hypotension
- flushing of skin
- headache
Tachyphylaxis - rapid tolerance
How does the heart adapt to congestive heart failure?
heart enlarges, blood backs up at lungs -> pulmonary congestion -> decreased ability to breathe
release of EPI, NE, AngII to increase HR, BP, vasoconstriction
increase blood vol via AngII -> increase in Na+ retention and activation of of Na+ / K+ exchanger
Ionotropic agents are used to treat what?
What is the logic behind their use?
Examples include?
tx for cardiac insufficiency
ions such as Ca2+ are essential to cardiac contraction. If you increase Ca2+, you increase contractility and can compensate for cardiac insufficiency.
examples:
the cardiac glycoside digoxin
dobutamine: strong ionotropic effect: increased force of contraction
Explain out loud to yourself in front of a bunch of people with your hands above your head while hyperventilating how digoxin works.
Toxicities?
cardiac glycosides inhibit Na+ - K+ ATPase -> Na+ remains high in the cell. This inhibits Na+ / Ca2+ exchanger ultimately preventing the loss of Ca2+. Calcium inside the membrane remains high = greater contractility
Toxicities:
-heart: arrhythmia (increased vagal tone
-CNS: yellow / green vision, hallucinations, CTZ = nausea and vomiting (monarchs)
effect of digoxin is greatly increased by hypokalemia
What is ultimately the best tx for congestive heart failure?
Name the drugs!
any agent that inhibits the body’s attempt to compensate:
- beta / alpha blockers
- ACE inhibitors
- diuretics
- vasodilators
Name the 3 oral drugs for erectile dysfuntion
MOA?
Should not be taken with?
SEs?
Metabolized by?
sildenafil
vardenafil
tadalafil
inhibit type 5 cGMP phosphodiesterase -> increase in cGMP -> vasodilation in arteries of corpus cavernosum
Should NOT be taken with alpha1 blockers or nitrates (too much dilation doeee)
SEs:
- slight BP decrease
- blue-green vision
- NAION - retinal damage from cGMP PDE inhibitors
- stroke
- myocardial infarction
metabolized by P450
Name an injectable PGE1 used to treat erectile dysfuntion
alprostadil
