Pharmacology of Drugs Used to Treat Angina Flashcards
What is angina
chest pain or discomfort due to coronary artery disease
What are typical symptoms of angina
Pressure, squeezing or pain in the center of heart
T/F: Angina pectoris is a consequence of myocardial oxygen demand exceeding myocardial oxygen supply
True
What causes the pain in angina
acidic metabolites accumulate and stimulate myocardial pain nerve endings
In a heart EKG what is the main difference for a patient with angina
ST segment is depressed
What are the three types of angina
Stable angina, unstable angina, and prinzemetal’s angina
What causes stable angina, what relieves stable angina
Stable plaque reduces maximal capacity of coronary artery, nitroglycerin and rest
What causes unstable angina
Atherosclerotic plaque ruptures causing a platelet pug to form blocking (clotting) flow to the heart muscle
What causes prinzmetal’s angina
Coronary artery spasm causes transient reduction of blood flow
T/F: Both unstable and stable angia are predictable and occur at rest and therefore should not be treated as an emergency
False: Stable angina is predictable while unstable angina occurs at resting and should therefore be treated as an emergency
What are the short term goals of angina/ long term goals
reduce or prevent anginal symtoms that limit exercise capability and impair quality of life/ prevent MI, arrhythmias, heart failure and extend the patient’s life
What is the do of organic nitrates for immediate short-term relief
Dilate systemic veins causing less venous return to the heart
What effects do organic nitrates have on the heart and its parameters
preload decreases, ventricular wall stress reduces, cardiac output reduces, reduces myocardial O2 demand (workload of heart reduces)
T/F: At higher doses arterioles are affected leading to blood pressure decreases but also possibly reflex tachycardia
True
T/F: Efficacy of nitrates pertains to their ability to act as a coronoary vasodilator
False: Efficacy of nitrates pertain to their ability to decrease myocardial oxygen demand rather than activity as a coronorary vasodilator
What is the MOA of nitroglycerin
Nitroglycerin enters vascular smooth muscle were it is converted to a nitric oxide (NO), NO activates guanyl cycles increasing cGMP causing dephosphorylation of myosin light phosphate all leading to relaxation
Why are sublingual nitrates preferred
bioavailabitly is best due to avoiding extensive first pass metabolism
If a nitrate is taken and there is no pain relief immediately what should the patient do
Contact emergency medical services if there is no pain relief after five minutes or if pain worsens while also taking more nitroglycerin in five minute intervals (up to 3 doses)
What is nitrate given orally with excellent bio-availability, what is the active metabolite
Isorbide dinitrate, mononitrate
What is the dosing for isosorbid mononitrate immediate release tablet (ISMO, sustained-release preparation (Imdur)
two times daily, 7 hours apart/ once daily
When is a sublingueal nitroglycerin tablet preferred
acute anginal attacks, acute prophylaxis
When would a long acting preparation be preffered
Sustained protection against angina attacks
What is the most common side effect, what causes this side effect, what is a another side effect
headache, cerebral dilation, flushing
What drugs do nitrates have interactions with, how long must the drugs be seperated
Viagra, Levitra, Cialis/ 24 hours (V and L), 48 hours (C)
How do erectile dysnfunction drugs interact with Nitrates
Sildenafil increase cGMP by inhibiting its breakdown by PDE-5 leading to severe hypotension
T/F: Tachycardia and dizzines are side effects from nitrates due to compensatory effects resulting from baroreceptor reflex
True
What is the first line therapy in chronic stable angina,
Beta blockers
How do beta blockers reduce myocardial oxygen demand (beta 1 effect) by decreasing what
Heart rate, contractility and blood pressure (reducing left ventricular wall stress)
What is the most common non selective beta blocker, cardioselective
propranolol, atenolol and metoprolol
T/F: CCBs would be used to treat acute angina
False: CCBs are used to treat stable (chronic) angina pectoris and vasospatic angina
What is the mechanism of the non-DHP CCBs
Blocks the initial calcium influx associated with formation of Calcium-tropoin complexes in the heart muscle therefore not allowing actin and myosin to cause contraction (decreased contractility)
What is the mechanism of the DHP CCBs
Blocks the initial calcium influx associated with formation of calcium-calmodium complexes in the vascular smooth muscle therefore not allowing actin and myosin to cause contraction (vasodilation)
T/F: Ranazoline is a last resort for patients that can be used with BB and nitrates and Amlodipine (not other CCBs) but may cause BP increase and prolongation of the QT interval.
True
