3.4.2. Anataginal Drugs

Question 1

What is the goal of therapy with antianginal drugs?

Answer 1

Restore the balance between oxygen supply and demand in the ischemic region of the myocardium

Question 2

What is the most important determinant of myocardial O2 demand?

Answer 2

HEART RATE - mediate high HRs w/antianginals to reduce symptoms and risk of sudden cardiac death

Question 3

aldehyde reductase enzymes are necessary to do what to anti-anginals?

Answer 3

these enzymes liberate NO and allow vasodilation to occur

Question 4

what drug does NOT need an aldehyde reductase? (ie, it spontaneously releases NO)

Answer 4

sodium nitroprusside

Question 5

anti-anginals initially act on what membrane protein, and cause an increase in concentration of what intracellular compound?

Answer 5

they activate guanylyl cyclase, which increases intracellular [cGMP]

Question 6

after cGMP-dependent kinases are activated by cGMP, what happens to myosin?

Answer 6

the contractile units are phosphorylated, inducing relaxation

Question 7

which experience greater degrees of vasodilation from these drugs: veins, or arteries?

Answer 7

VEINS&raquo_space; arteries. recall that venodilation induces a DECREASE IN PRELOAD that is desired in Pts w/angina because it decreases myocardial O2 demand

Question 8

list three of the clinical uses of anti-anginals

Answer 8

angina, acute coronary syndrome, pulmonary edema

Question 9

list four of the reported side effects of nitrates

Answer 9

reflex tachycardia (treat with beta-blockers), hypotension, flushing, headache

Question 10

these drugs act on which arteries to specifically prevent coronary steal?

Answer 10

they dilate the large epicardial coronary vessels (vasodilators in general affect the entire body, as opposed to the heart specifically)

Question 11

what is another useful way to decrease myocardial O2 demand?

Answer 11

Modest declines in systolic blood pressure (afterload) are useful for this

Question 12

Fill in the blanks:
Nitrates have a ____ bioavailability due to metabolism by the liver, and have a very ____ half life with a fairly quick tolerance buildup

Answer 12

… they have a LOW bioavailability … and have a very SHORT half life …

(use these drugs PRN, like advil)

Question 13

what is an absolute CONTRAINDICATION of nitrates?

Answer 13

NEVER USE NITRATES WITH SILDENAFIL - together they can cause hypotension, coronary steal, and MI

Question 14

what are FOUR physiological actions of Ca-channel blockers?

Answer 14

1) Arteriolar dilator: reduce afterload
2) Reduce cardiac contractility
3) Decrease the heart rate
4) Decrease coronary resistance to increase coronary blood flow

Question 15

what are three uses of Ca-channel blockers?

Answer 15

• Angina (these are very good for variant/Prinzmetal angina)
• Acute MI
• Hypertension
• ** Ca-channel blockers are the drugs of choice for treating STABLE and VARIANT angina ***

Question 16

List FIVE side effects/contraindications of Ca-channel blockers

Answer 16

1) Heart failure
2) AV block
3) Bradycardia
4) Cardiac arrest
5) Cardiac depression

Question 17

How do Verapamil and diltiazem act to decrease myocardial O2 demand?What is a side effect of these drugs

Answer 17

they decrease HR & contractility (like beta-blockers).

Question 18

How do Nifedipine and nisoldipine act to decrease myocardial O2 demand?

Answer 18

they decrease afterload via vasodilation.

Question 19

What is a side effect of Verapamil and diltiazem?

Answer 19

verapamil & diltiazem can cause constriction, bradycardia, AV block

Question 20

What is a side effect of Nifedipine?

Answer 20

Nifedipine may cause reflex tachycardia (increases O2 demand)

Question 21

what are FOUR side effects/contraindications of Beta blockers?

Answer 21

1) Asthma (Beta2 receptors)
2) Erectile Dysfunction
3) Depression
4) Insomnia (if person has insomnia caused by variant angina, Beta blockers may actually worsen episodes of variant angina)