pharmacology: antianginal drugs

Question 1

drug strategies in stable and vasospastic angina

Answer 1

increased oxygen delivery by decreased vasospasm (nitrates and CCBs)
and decreased oxygen requirement by decreased TPR, CO, or both (nitrates, CCBs and beta blockers)

Question 2

nitrates mechanism

Answer 2

prodrugs of NO

venodilation –> decreased preload –> decreased cardiac work –> decreased oxygen requirement

Question 3

what are the nitrates?

Answer 3

nitroglycerin (sublingual, transdermal, IV)

isosorbide (oral, extended release for chronic use)

Question 4

nitroglycerin and isosorbide side effects

Answer 4

flushing, headache, orthostatic hypotension

reflex tachycardia and fluid retention

Question 5

which CCB is an important vasospastic angina agnet?

Answer 5

nifedipine (decrease contractility and increase vasdilation by preventing influx of Ca required for muscle contraction)

Question 6

NO mechanism

Answer 6

made by endothelial cell - increases guanylyl cyclase hish converts GTP or CGMP which causes relaxation

Question 7

what are beta blockers contraindicated in?

Answer 7

vasospastic angina (a reversible decrease in coronary blood flow)

Question 8

ranolazine mechanism

Answer 8

blocks late inwards Na+ current in cardiac myocytes thereby decreasing calcium accumulation
results in decreased end diastolic pressure and improvement of diastolic coronary flow

Question 9

which beta blockers should NOT be used in angina? why?

Answer 9

beta blockers with intrinsic sympathomimetic activity (acebutolol and pindolol)