Drugs used in ACS/Stable Angina Flashcards
How can surgery be used to treat stable Angina?
–
Surgery and interventional cardiology approaches are effective
•Coronary artery bypass grafting
•Percutaneous coronary intervention (PCI)
•Stent expandable tube used as scaffolding to keep vessel open
–Reocclusion
–Drug eluting stents ( antiproliferative drugs
Pharmacotherapy is not effective in increasing blood flow through the stenotic coronary artery into the ischemic area
what is the approach to treat stable angina
Reduce myocardial oxygen demand
- HR
- COntractility
- Preload
- Afterload
what are the 3 Nitrates?
– Nitroglycerin (generic, Nitro Dur , Nitro Time) – Isosorbide dinitrate – Isosorbide mononitrate
MOA of Nitrates
activate cGMP that will activate protein kinase G that causes Myosin LC dephosphorylation that causes Smooth muscle relaxation
also opens potassium chanels that causes hyperpolarization and reduced calcium entry
all helps to reduce Preload
what is the sensitivity of vasculature to nitrate induced vasodilation
Veins
Large arteries
Small arteries and arteioles
Adverse effects and contradictions of Nitrates
•Headache (due to meningeal vasodilation)
–Nitrates are contraindicated if intracranial pressure is
elevated
•Orthostatic hypotension
•Increased sympathetic discharge
–Tachycardia
–Increased cardiac contractility
•Increased renal Na and H 2 O reabsorption
what are 3 drug interactions with Nitrates?
All three drugs used in erectile dysfunction
–Sildenafil
–Vardenafil
–Tadalafil
•Inhibit cGMP phosphodiesterase 5, increase cGMP
•Minimal effects on hemodynamics when administered alone in men with coronary artery
disease
•Combination with nitrates causes severe increase in cGMP and a dramatic drop in BP
•Acute myocardial infarctions have been reported
what are the 3 Non cardioactive Calcium channel blockers
(Dihydropyridines)
- Amlodine long acting
- Nifedipine (short acting)
- Nicardipine (short acting)
what are 2 Cardioactive Dihydropyridines?
Diltiazem
Verapamil
how does dihydropyridines and Cardioactive CCBs affect the heart
–Dihydropyridines •Vascular smooth muscle -decrease PVR and afterloadd -arteries affected more than veins -more effective vasodilaters than cardioactive CCBs
–Cardioactive CCBs
•Vascular smooth muscle
•Cardiac muscle (decreased contractillity)
•Cardiac pacemakers cells (reduced HR)
Major adverse effects of CCBS
•Major
–Cardiac depression, cardiac arrest, and acute heart failure
cardioactive CCBs)
–Bradyarrhythmias , atrioventricular block cardioactive
CCBs)
–Severe hypotension
–Short acting dihydropyridine CCBs vasodilation triggers
reflex sympathetic activation
–Nifedipine (immediate release) increases the risk of MI in
patients with hypertension slow release and long acting
dihydropyridines are better tolerated
•Minor
–Flushing, headache, anorexia, dizziness
–Peripheral edema
–Constipation (verapamil)
what are the 4 Beta blockers used in stable angina
Propranolol
Nadolol
Metoprolol
Atenolol
Mechanism of Action of Beta blockers?
Decreased Myocardial oxygen demand
-Decrease in HR leads to improved myocardial perfusion
and reduced oxygen demand at rest and during exercise
–Decrease in cardiac contractility
–Decrease in blood pressure leads to reduced afterload
Advese effects of Beta Blockers
–Reduced cardiac output
–Bronchoconstriction
–Impaired liver glucose mobilization
–Produce an unfavorable blood lipoprotein profile (increase VLDL and
decrease HDL)
–Sedation, depression
–Withdrawal syndrome associated with sympathetic hyperresponsiveness
Contraindictions of Beta Blockers
–Asthma –Peripheral vascular disease –Type 1 diabetics on insulin –Bradyarrhythmias and AV conduction abnormalities –Severe depression of cardiac function