CAD Pharmacology Flashcards
Aspirin
Class: NSAID
Mech: Irreversible inhibition of platelet cyclooxygenase which blocks thromboxane A2 formation preventing platelet aggregation.
Thera: Reduction of adverse events (MI, stroke, death) in those with stable angina, unstable angina, MI
Also used as prophylaxis in asymptomatic individuals
Misc: Can cause asthma if allergic
Ticlopidine
Class: Thienopyridine derivative
Mech: Inhibits platelet aggregation induced by adenosine diphosphate. It also reduces blood viscosity by decreasing plasma fibrinogen and increases red cell deformity
Thera: Aspirin alternative although has not shown decrease in adverse events in patients with stable angina
Tox: Neutropenia and rarely TTP
Clopidogrel
Class: Thienopyridine derivative
Mech: Selectively and irreversibly inhibits the binding of ADP to its platelet receptor (glycoprotein IIb/IIIa) preventing platelet aggregation
Thera: Great antithrombotic (used for new stents)
Tox: Serious bleeding
Misc: Not for chronic use due to serious risk for bleed. Cannot do surgery while patient is on this.
Prasugrel
Class: Thienopyridine
Mech: Irreversibly binds to the P2Y12 receptor (GPIIb/IIIa) preventing ADP from binding and platelets from aggregating
Thera: Reduce thrombotic cardiovascular events during an ACS for which patient received PCI (most potent)
Tox: Serious risk of bleed
Misc: Limited to patients less than 75 years old, greater than 60kg and no history of CVA or TIA
Ticagrelor
Mech: Similar in structure to ADP so provides reversible block of GPIIb/IIIa
Thera: ACS
Tox: Bleeding greater than clopidogrel
Misc: Does not require hepatic activation
Faster onset of action and eliminated faster requiring bid dosing
Dipyridamole
Class: Pyrimido-pyrimidine
Mech: Increases cAMP in platelets which inhibits PDE5, activates adenylate cyclase, inhibits uptake of adenosine from vascular endothelium and RBCs
Thera: Decrease peripheral vascular disease therefore used for stress testing as dilates coronary arteries (increased extracellular adenosine)
Tox: Can lead to coronary stealing (exercise induced ischemia)
Cilostazol
Class: Quinolinone derivative
Mech: Inhibits cellular phosphodiesterase increasing cAMP which results in inhibition of platelet aggregation and also causes vasodilation
Thera: Treatment for claudication in people with peripheral vascular disease
Tox: Increased morbidity/mortality in patients with CHF
ACE inhibitors
Mech: Blocks endothelial ACE from converting AI to AII and also prevents the breakdown of bradykinin (potent vasodilator)
Thera: Add-on antihypertensive for anyone with chronic kidney disease/proteinuria, CHF, LVH, or post MI (prevents remodeling)
Also reduces risk of future CAD events
May reduce risk for diabetes
Tox: Cough, hypotension, hyperkalemia, angioedema, decreased renal function
Misc: Short-acting, contraindicated in pregnancy, renal artery stenosis, hyperkalemia, and prior angioedema (no ARB either), caution in renal failure
Beta Blockers
Metoprolol, Atenolol, Bisoprolol
Mech: Decrease contractility, HR causing reduced O2 demand Also a class II antiarrhythmic by inhibiting SNS influence on cardiac electrical activity, increases AP duration and effective refractive period in AV node
Thera: Prevent MIs, prevent sudden cardiac death, increase survival post-MI, reduce angina and ischemia
Tox: Fatigue, worsening claudication, impotence, decreased exercise tolerance, lethargy, insomnia
Misc: Contraindicated in severe brady, high degree AV block, sick sinus syndrome, unstable LV failure, asthma, severe depression, peripheral vascular disease
Nitrates
Class: Vasodilator
Mech: Endothelium independent vasodilator (Activates guanylyl cyclase to form cGMP which inhibits Ca entry into the cell). Predominately a venodilator (relieves preload and subsequent contractility) Endothelial effects (inhibits platelet aggregation, inhibits leukocyte endothelial interactions (anti-inflammatory).
Thera: Acute episodes of angina
Tox: Tolerance with chronic use (need nitrate free periods of 8-12 hours), headaches, hypotension, activation of Bezold-Jarisch reflex (causes bradycardia)
Misc: Contraindicated in hypertrophic cardiomyopathy, severe aortic stenosis, significant hypotension, use of PDEi (ED treatments)
Dihydropyridines
Nefedipine (1st generation), Amlodipine, Felodipine, Isradipine
Class: Ca Channel blockers
Mech: Interact with L-type VG Ca channels decreasing calcium entry into the vascular smooth muscle cell, preventing contraction, and causing dilation of coronary arteries and arteriolar resistance arteries (Nefedipine is 1st generation and has some negative inotropic effect)
Thera: HTN, Raynauds, angina (3rd choice drug) for Nefedipine and Amlodipine
Tox: Leg edema, HF, AV nodal blockade, bradycardia, flushing, headache, constipation, hypotension
Misc: Contraindicated in overt decompensated HF, bradycardia, sinus node dysfunction, high-degree AV block
Nondihydropyridines
Verapamil, Diltiazem
Class: Calcium channel blocker
Mech: Interact with L-type VG Ca channels decreasing calcium entry into the vascular smooth muscle cell, preventing contraction, and causing dilation of coronary arteries and arteriolar resistance arteries
Causes decreased contractility, firing rate of aberrant pacemaker sites, and conduction velocity, prolongs repolarization in SA node and AV node (decreases HR). LESS VASODILATION
Thera: HTN, anti-anginal (chronotropic effects) Arrhythmic
Tox: Leg edema, bradycardia, AV nodal blockade, hypotension, worsening heart failure, constipation, headache, flushing
Misc: Contraindicated in overt decompensated HF, bradycardia, sinus node dysfunction, high-degree AV block
