Cardiac drugs

Question 1

dofentilide

Answer 1

• MOA: Class III antiarrhythmic (K+ channel blocker; “K=AIDS” –> D=dofentilide); inhibit repolarization –> increases AP duration and ERP
• SEs: QT prolongation

Question 2

hydralazine

Answer 2

• MOA: direct vasodilator; often used in combination w/ isosorbide dinitrate for tx of heart failure
• SEs: tachycardia, orthostatic hypotension

Question 3

spironolactone

Answer 3

• MOA: aldosterone-antagonist
• renal: mild diuretic effects, K-sparing
• cardiac: block local aldosterone toxocity –> myocardial fibrosis / hypertrophy

Question 4

nitroglycerin

Answer 4

-first-line for rapid symptom relief of stabls angina
MOA: direct smooth muscle dilator that results in:
1) vasodilation of peripheral veins/arteries, predominantly venodilation
2) decreased myocardial O2 demand due to decreased preload (decreased LV eDV and pressure = decreased wall stress)
3) modest reduction in afterload
4) mild coronary artery dilation and reduction of coronary vasospasm

Question 5

amioloride

Answer 5

• K-sparing diuretic; acts on principal cells to block ENaC, leading to reduced Na resorption in the collecting duct