Cardio Pharmacology Flashcards
Nifedipine
Calcium channel antagonist, DHP. Binds while L-type channel is resting, most peripheral smooth muscle (vasodilation) where channels are more frequently resting.
Amlodipine
Calcium channel antagonist, DHP. Binds while L-type channel is resting, most peripheral smooth muscle (vasodilation) where channels are more frequently resting.
Diltiazem
Calcium channel antagonist, Non-DHP. Binds to L-type channel when OPEN - most effective in cardiac myocytes (which frequently depolarize). Decrease cardiac contractility. Induce Coronary Vasodilation. Lowers automaticity in SA/AV nodes (Reduces HR).
Verapamil
Calcium channel antagonist, Non-DHP. Binds to L-type channel when OPEN - most effective in cardiac myocytes (which frequently depolarize). Decrease cardiac contractility. Induce Coronary Vasodilation. Lowers automaticity in SA/AV nodes (Reduces HR).
Furosemide
Loop diuretic. Binds Na/K/Cl transporter in Ascending tubule,
HCTZ (hydrochorthiazide)
Thiazide diuretic. Acutely Acts on distal tubule, fluid excretion, Na+ excretion, lower blood volume, less BP. Chronically - NO release, vasodilation, decreased PVR - so, volume recovers but BP stays low.
Losartan
ARB (angiotensin receptor blocker). Blocks AT1 receptor for A-II. Blocks TGF-B1 activation. Downside: DoesnÕt stop cleavage of bradykinin.
Enlalapril
ACEi. Blocks conversion of A-I to A-II, which prevents downstream actions of A-II. Also blocks cleavage of bradykinin, so it can go on to do great things (NO release).
Direct Renin Inhibitors
Éinhibits renin.
Phenoxybenzamine
Non-selective alpha blocker. Vasodilation, decreased PVR.
Prazosin
Selective alpha blocker. Alpha 1 and 2. Vasodilation, decreased PVR.
Doxazosin/Terazosin
Selective alpha blocker, Alpha 1 only. Vasodilation, decreased PVR.
Clonidine
Central alpha agonist, alpha 2. Stimulate pre-gang alpha-2 receptors in medulla, reduction of sympathetic outflow. Unopposed vagal tone. Decreased PVR, HR, CO, BP.
Spironolactone
Aldosterone antagonist/mineralocorticoid receptor antagonist. Potassium sparing diuretic.
Hydralazine
Arterial vasodilator. Mechanism unknown. Arteriolar dilation, doesn’t affect veins. Mostly renal, periph, splanchnic, and coronary arterties. Decrease BP.
Sodium nitroprusside
Arterial vasodilator. Metabolised by SMCs into NO –> vasodilation, decrease in PVR. Byproduct = cyanide, which is metabolized by RBCs by rhodanase with help of cofactor sodium thiosulfate. Sodium thiosulfate added to solution to prevent cyanide tox. Unstable in sunlight, they wrap it in foil.
Nitrates
Venodilator. Converts to NO in endothelium, gas diffuses to receptors. Activates guanylyl cyclase which forms c-GMP which inactives myosin light-chain kinase É causes SMC relaxation, esp in veins, decreased platelet aggregation. Also GI and bronchial relaxation. Decreases venous blood return, decreases LV cavity size and ejection force, decreases systolic wall stress, myocardial O2 demand. Increases endocardial perfusion. Decreases thrombs.
Propranolol
Non-selective beta blocker. Reduce heart rate and renin release by inhibiting sympathetic nervous signaling. Antagonize these systems: 1) Alpha1/2 - increase in vasoconstriction 2) Beta1 - acts on SA/AV nodes and causes increase in chronotropy and ionotropy 3) Beta2 - vasodilation of cardiac vessels and bronchodilator
Metoprolol
Selective beta blocker.