CARDIOMEDS MOA Flashcards
Antagonizes both β1 and β2 receptors this inhibiting effects of catecholamines on these receptors
• CV effects
Decrease contractility and heart rate
• Non-CV effects
May increase peripheral resistance
Bronchospasm
Non-selective agents
Nadolol, Pindolol, and Propranolol a
Antagonize β1 receptors to a greater extent than β2 receptors in typical doses
• CV effects
Decrease contractility and heart rate
Selective
Acebutolol, bisoprolol, esmolol, atenolol, and metoprolol a
They possess non-selective beta blocking activity like propranolol and alpha blocking activity like prazosin Effects seen: ▪ Decrease heart rate ▪ Decrease contractility ▪ Vasodilation
Alpha/beta adrenergic receptor antagonists
Labetalol, carvedilol (3rd gen. beta blockers)
o Block peripheral alpha 1 receptors → cause vasodilation secondary to inhibiting catecholamines mediated
vasoconstriction
▪ They block both arterial and venous alpha receptors
Decrease afterload of heart
Decrease peripheral vascular resistance
Selective alpha 1 adrenergic blockers
Doxazosin, prazosin, terazosin, tamsulosin (prostate selective)
Alpha 1A and 1D antagonistic effect increases selectivity for prostate
Tamsulosin
alpha 1 selective antagonist approved for BPH
Alfuzosin
Alpha 2 receptors are located in CNS→ presynaptic receptors so stimulation will decrease sympathetic outflow
Central acting alpha 2 adrenergic receptor agonist
Clonidine, guanabenz, guanfacine, methyldopa
inhibit conversion of angiotensin I to angiotensin II
Angiotensin inhibitors
ACEIs
Blocks angiotensin II from binding to the angiotensin type 1 receptor (AT1)→ blocking vasoconstriction and aldosterone
secreting effects of angiotensin II
Blocks the effect of ATII regardless of whether its generated by ACE, or some other enzymatic route
Does not interfere with metabolism of kinins and neuropeptides
Angiotensin Receptor Blockers
Metabolically converted to nitric oxide in vascular smooth muscle
vasodilating effects and reduces platelet adhesion and aggregation
Nitrates
Arteriolar vasodilator
Vasodilation causes SNS stimulation with increased heart rate and contractility, increased plasma renin activity and fluid
retention
Miscellaneous Vasodilators
Hydralazine
Venous and arteriolar vasodilator
Metabolized by smooth muscle cells to active metabolite NO → activates guanylate cyclase to form cGMP→ vasodilation
Unlike minoxidil, hydralazine, and other arteriolar vasodilators, SNP usually produces only a modest increase in HR and an overall decrease in myocardial O2 demand
Miscellaneous Vasodilators
Sodium Nitroprusside
Arteriolar vasodilator
Relaxation of smooth muscle with little effect on veins
Decrease SVR and BP by triggering SNS, inhibiting vagal tone, and renal homeostatic mechanisms leading to increase HR
CO and sodium/ fluid retention
Miscellaneous Vasodilators
Minoxidil (Rogaine)
Dopamine 1 agonist
Binds D1-like DA receptors and has moderate affinity for alpha 2 receptors (minimal adrenergic effects)
Binding D1 produces peripheral vasodilation with increase renal blood flow, diuresis and natriuresis
6x more potent than DA for renal vasodilation
Miscellaneous Vasodilators
Fenoldopam
Anti-anginal agent that doesn’t affect HR or BP
Inhibits late phase of inward sodium channel in ischemic cardiac myocytes during cardiac repolarization
Used as an additive agent after beta-blocker, nitrate and amlodipine
Miscellaneous Vasodilators
Ranolazine
Prevent breakdown of naturetic peptides
Naturetic peptides produce vasodilation and increase sodium excretion in kidneys
Neprilysin Inhibitor
Angiotensin II receptor blocker and neprlysin inhibitor
Produces vasodilation and increases sodium excretion
Enteresto
Calcium channels are located throughout the body
Calcium is needed for cardiac and smooth muscle contraction, and pacemaker activity in heart (SA node depolarization, AV node
conductance)
calcium channel blockers
these diuretics are freely filtered into the lumen of the
nephron and not reabsorbed
This causes an increase in solutes in the nephron and
water follows the high solute concentration
diuretics
Osmotic Diuretics: Mannitol
this diuretic Inhibits NaCl reabsorption into the distal convoluted tubule (DCT)
increase calcium reabsorption in the DCT
diuretics
Thiazide and Thiazide-Like Diuretics
this diuretic binds to the Na+/K+/2Cltransport
system blocking the reabsoprtion of Clthus
sodium and water will follow
Loop Diuretics
Bumetanide, Ethacrynic acid, Furosemide, Torsemide
this diuretic Inhibits aldosterone effects in the cortical collecting tubule and late distal tubule
Potassium Sparing Diuretics
Spironolactone/Eplerenone
this diuretic Inhibits sodium transport through ion channels in the cortical collecting tubule and late distal tubule
Potassium Sparing Diuretics
Amiloride and Triamterene
this diuretic is found in the brush border cells in the lumen of the nephron
Inhibition of this enzyme decreases sodium bicarb reabsorption in the PCT → water follows
May cause metabolic acidosis which decreases the effectiveness for diuresis
diuretics
Carbonic anhydrase inhibitors
