Anti-anginal drugs Flashcards
how long do angina pectoris usually last?
15s - 15 mins
what is the immediate cause of angina pectoris?
imbalance between myocardial O2 supply and demand
what is the differnce in the vessels in stable angina vs unstable angina
both will have narrowed lumen due to a plaque but with unstbale angina the plaque will be ruptured and will have platelet aggregation and thrombus formation
is there plaques or lumen narrowing associated with variant angina?
NO, has innappropriate vasopasm
in addition to plaque rupture, what is another cause of unstable angina?
if the diseased coronary artery endothelium is unable to produce NO and prostacyclin tha inhibit platelet aggregation and clot formation
variant and unstable angina can result if the endotheiium is unable to make _____ and _____ which inhibit _______ and _______
NO and prostacyclin; inhibit platelet aggregation and clot formation
causes of variant/prinzmental angina
- enhanced sympathetics- damaged endothelium cannot make NO
__________ drugs are used to increase oxygen delivery AND decrease oxygen demand
vasodilators
what 4 classes of drugs are used to treat angina?
- nitrates: isosorbide dinitrate, nitroglycerin, sodium nitroprusside- beta blockers- calcium channel blockers: amlodipine, nifedipine, diltiazem and verapamil- sodium channel blockers: ranolazine
nitrates cause what to O2
decrease in the myocardial oxygen demand via systemic vasodilation
increase oxygen delivery by dilating coronary vessels
what are three functions of NO?
- vasodilation- anti-thrombotic- anti inflammatory(all involve the NO stimulated formation of cGMP)
when is IV nitroglycerin given?
unstable angina + acute heart failure
_______ is the first line treatment for acute anginal symptoms
sublingual nitroglycerin
what nitrate is given for prophylaxis? and why?
isosorbide mononitrate and is given ORALLY
takes longer to see effects (1hr)
how can nitrate tolerance be overcome:
daily nitrate free intervals (10-12 hr)
what is the most common AE of nitrates?
headache due to cerebral vasodilation
high doses of nitrate can cause:
- postural hypotension
- facial flushing
- reflex tachycardia
_______ is contraindicated with nitrates
sildenafil
what is the MOA of sildenafil?
inhibits the enzymes phosphodiesterase 5 which then will inhibit the breakdown of cGMP leading to an increase in available cGMP causing vasodilation
________ is used to treat severe hypertensive emergencies and severe heart failure
sodium nitroprusside
cyanide intoxication is an AE of ______
sodium nitroprusside
what patients are recommend to use beta blockers?
patients with stable angina and have acute coronary syndrome or those with left ventricular dysfunction
beta blockers are contraindicated in the treatment of _______
variant angina; don’t want to block the beta2 vasodilatory effect (even when you give a beta 1 selective because selective has some effect on beta2)
what drugs are used to treat variant angina?
calcium channel blockers or nitrates
NOT BETA BLOCKERS
_____ type calcium channels is dominant in cardiac and smooth muscle
L type
what are the dihydropyradines and what do they act on?
nifedipine and amlodipine;
mainly acts on VASCULATURE
what should you not give patients who have a preexisting cardiac depression or with an AV conduction abnormalities
verapamil (calcium channel blockers that are specific to the heart)
digoxin levels can increase when given _____ because it can displace it from its binding sites
verapamil (calcium channel blocker)
which non dihydropyradine decreases HR more?
verapamil
MOA of ranolazine?
blockade of sodium current that facilitates the calcium entry via Na/Ca exchanger; usually this exchange will bring sodium in and push calcium out but in this when there is angina there is less ATP and so the Na/K ATPase pump doesn’t work so there is more sodium inside the cell thus REVERSING the direction of the Na/Ca exchanger
ranolazine lead to _______ intracellular calcium
decreased;
adverse effects of ranolazine
last line treatment; QT interval prolongation
treatment regiment for stable angina:
nitrates > beta blockers > calcium channel blockers > ranolazine
treatment regiment for variant angina?
nitroglycerin and calcium channel blockers (NO beta blockers)
can you use beta blockers to treat angina in a patient with chronic renal disease?
yes, but after giving nitrates, calcium channel blockers have shown to give better outcomes
what is the effect on the end diastolic volume when giving beta blockers or calcium channel blockers?
EDV will increase (depends on patient)
when nitrates + beta blockers or calcium channel blockers are given, what are the effects on:
HR, atrial pressure, EDV, contractility and ejection time?
HR: decrease atrial pressure: decrease EDV: none/decrease contractility: none ejection time: none
