PBL: CHF Drugs

Question 1

Nitroglycerine

Answer 1

MOA: increase cGMP in smooth muscle, relaxation. dilates veins >> arteries, decreases preload

TU: pulmonary edema, angina, acute coronary syndrome

Adverse: reflex tachycardia (Tx: beta blockers), hypotension, flushing, headache

“Monday disease” possible if exposed during workweek, become tolerant and hypertensive on weekend when no exposure

Question 2

Furosemide

Answer 2

Class: sulfonamide loop diuretic

MOA: NKCC symporter inhibitor of thick ascending limb of loop of Henle

TU: CHF + other edematous situations, HTN, hypercalcemia

Adverse: OH DANG!

ototoxicity, hypokalemia, dehydration, allergy, nephritis, gout

Question 3

Enalapril

Answer 3

Class: ACE inhibitor

MOA: inhibit ACE, suppresses RAAS system, decrease GFR by preventing constriction of efferent arterioles. elevation of renin levels to compensate. prevents activation of bradykinin (potent vasodilator)

TU: HTN, heart failure, diabetic nephropathy

Adverse: cough, angioedema, teraogen, creatinine, hyperkalemia, hypotension

Question 4

Metoprolol

Answer 4

Class: beta-blocker

MOA: decrease cAMP -> decrease Ca²⁺ currents -> decrease phase 4 slope

TU: supraventricular tachycardia, slowing ventricular rate during a-fib and atrial flutter

Adverse: impotence, COPD and asthma exacerbation, bradycardia, AV block, CHF, mask signs of hypoglycemia

Question 5

Eplerenone

Answer 5

Class: K⁺-sparing diuretics

MOA: aldosterone receptor antagonists in cortical collecting tubule (Na⁺ channels in cortical collecting tubule)

TU: CHF, K⁺ depletion, hyperaldosteronism

Adverse: hyperkalemia, endocrine effects

Question 6

Digoxin

Answer 6

Class: cardiac glycoside

MOA: Na+/K+ ATPase inhibitor, leads to indirect inhibition of Na+/Ca2+ exchanger/antiporter, increased [Ca2+]i –> positive ionotropy (increases contractility), stimulates vagus nerve

TU: CHF, a-fib

Adverse: cholinergic–nausea, vomitting, diarrhea, blurry yellow vision, increased PR, decreased QT segment, ST scooping, T-wave inversion, arrhythmia, AV block, hyperkalemia

Question 7

Hydralazine

Answer 7

Class: direct vasodilator

MOA: increase cGMP -> sm. muscle relaxation, arterioles > veins, afterload reduction

TU: severe HTN, CHF, first line for HTN in pregancy with methyldopa, frequently coadmin w/ beta-blocker to prevent reflex tachycardia

Adverse: compensetory tachycardia, fluid retention, nausea, headache, angina, lupus-like syndrome

Question 8

Isosorbide dinitrate

Answer 8

Class: nitrate

MOA: same as nitro, longer t_1/2 than nitro

TU:

Adverse: