Chapter 17 Vasodilator Drugs

Front 1

Vasodilators are useful in treating what (2) conditions?

Back 1

CHF and HTN

Front 2

What is the role of Vasodilators in CHF?

Back 2

The body's normal physiologic response in CHF is vasoconstriction. Excessive vasoconstriction can lead to pulmonary congestion (venous) and/or decreased Cardiac Output(arteriolar). This can be modulated by VD's.

Front 3

What is the role of Vasodilators in HTN?

Back 3

Decrease arteriolar resistance with subsequent drop in Blood Pressure.

Front 4

Give examples of different Vasodilators based on location of action (i.e. Venous, Arteriolar or both).

Back 4

Venous = nitrates;
Arteriolar = Hydralazine, minoxidil;
Both = ACE In.,alpha-blockers, Na nitropruside

Front 5

TRUE/FALSE - Angiotensin Converting Enzyme leads to increase AII, which binds to AT1 causing increased natriuresis.

Back 5

False - ACE does lead to increased AII, which binds to AT1, but causes decreased natriuresis.

Front 6

What are the 2 physiologic effects of Angiotensin II binding to AT1?

Back 6

1. Vasoconstriction;
2. release of aldosterone;

Front 7

What are the 3 net effects of ACE inhibitors?

Back 7

1. decreased Arteriolar Pressure (vasodilation Bradykinin accumulation); 2.Facilitate natriuresis;
3. Reduce Ventricular Remodeling

Front 8

TRUE/FALSE - ACE inhibitors are only effective in hypertensive patients with "high renin"

Back 8

False - ACE Inhibitors are effective regardless of Serum Renin levels.

Front 9

TRUE/FALSE - Diuretics are the perferred treatment in diabetics with HTN to slow diabetic nephropathy.

Back 9

False - ACE Inhibitors

Front 10

BP = (?) x (?)

Back 10

BP = CO x TPR

Front 11

In CHF, What effect does ACE inhibitors have on PVR, AL, PL, & CO?

Back 11

PVR, AL, PL decrease;
CO increases

Front 12

TRUE/FALSE - Side Effects of ACE inhibitors are more common in patients with intravascular volume depletion.

Back 12

TRUE

Front 13

What are the side effects of ACE Inhibitors?

Back 13

Rare: Hypotension, Hyperkalemia, Renal Insuffiency, Cough

Front 14

What is the mechanism of action of AT1R antagonists (ARBs)?

Back 14

Competitive inhibitors of AII by binding to AT1 R, thereby inhibit vasoconstriction and aldosterone release.

Front 15

TRUE/FALSE - ARBs are more effective than ACE inhibitors at blocking the renin-Angitotensin system, and equally effective as an anti-hypertensive.

Back 15

True

Front 16

What are the side effects of ARBs?

Back 16

Hypotension, Hyperkalemia, NOT cough

Front 17

Give 4 examples of Direct Acting Vasodilators?

Back 17

Hydralazine, minoxidil, Na nitroprusside, diazoxide.

Front 18

ACE inhibitors can precipate renal failure in ?

Back 18

bilateral renal stenosis

Front 19

Hydralazine and Minoxidil can cause reflex Tachycarida, causing precipitation of what? This is prevented by what concomitant treatment?

Back 19

Myocardial Infarction with underlying CAD.
Addition of a Beta Blocker.

Front 20

TRUE/FALSE - Hydralazine, an arteriolar dilator,has low bioavailability due to limited absorption.

Back 20

FALSE - Bioavailabilty is determined by rate (slow/fast) acetylation of drug, through 1st pass through the liver.

Front 21

What are the side effects of Hydralazine?

Back 21

HA, palpitations, flushing, nausea, anorexia, SLE like syndrome

Front 22

What is the mechanism of action of Minoxidil?

Back 22

Increased K channel permeability leading to hyperpolarization, smooth muscle relaxation and decreased renal perfusion.

Front 23

What are the side effects of minoxidil?

Back 23

reflex Tachycardia, fluid retention, hypertrichosis, occasional pericardial effusion

Front 24

TRUE/FALSE - Minoxidil's primary clinical indication is in severe, intractable HTN.

Back 24

TRUE

Front 25

Na Nitroprusside is used in HTN/CHF emergencies. Why?

Back 25

IV continous infusion with 30 second response.

Front 26

What precautions (2) must be taken with Na Nitroprusside?

Back 26

Beta blocker to prevent reflex tachycardia and Cyanide toxicity.

Front 27

What is the mechanism of action of Na Nitroprusside?

Back 27

RBC's metabolism of the drug results in NO release(vasodilator) and cyanide byproduct.

Front 28

TRUE/FALSE - Fenoldopam causes arteriolar dilation, but unlike other Direct acting VD's it enhances renal perfusion.

Back 28

True

Front 29

In what condition is Fenoldopam, an DA1 Receptor agonist, contraindicated?

Back 29

Glaucoma patients

Front 30

What is the mechanism of Calcium Channel Blockers (CCBs)?

Back 30

Calcium Channel Blockers (CCBs) prevent Ca influx via voltage gated Channels L & T.

Front 31

What is the effect of CCBs on VSM & CSM?

Back 31

VSM can't contract leading to vasodilation. CSM interferes with excitation-contraction coupling (can slow depolarizatoin also).

Front 32

What are the physiologic effects of CCBs?

Back 32

Negative inotropic effect and Vasodilation.

Front 33

What are the indications for CCBS?

Back 33

Angina pectoris, Coronary Artery spasm (Variant Angina), HTN, Supraventricular Arrhythmias

Front 34

What are the side effects of CCBs? Why are short acting CCBs not used?

Back 34

Side effects are hypotension, edema & brady arrhythmias. Short acting CCBs have higher incidence of MI in HTN/CAD patients.

Front 35

TRUE/FALSE - Nitrates, such as nitroglycerin, cause vasodilation via NO production, resulting in vasular smooth muscle relaxation.

Back 35

True

Front 36

What is the major condition in which Nitrates are used?

Back 36

Angina Pectoris

Front 37

At which dosage (high/low), do nitrates preferentially vasodilate systemic veins leading to venous pooling?

Back 37

Low doses

Front 38

What are the side effects of nitrates?

Back 38

flushing, HA, Hypotension, reflex Tachycardia