Vasodilators

Question 1

Specific cause for HTN is identified in what % of the population?

Answer 1

10-15%

Question 2

What is essential HTN?

Answer 2

HTN with no cause found, aka primary HTN

Question 3

What are some specific causes of HTN?

Answer 3

pheo, thyroid, parathyroid, cushings, aldosterone issues, renal artery stenosis, genetics, gestational, steroids, oral contraceptives, long term NSAIDS

Question 4

What is the treatment for stage I HTN?

Answer 4

usually diet/exercise, decrease salt

Question 5

What is the treatment for stage 2 HTN?

Answer 5

prescribe: 1st thiazide diuretics. cheap, minimal s/e, dosed once daily

Question 6

What are the 4 anatomic sites at the body that control blood pressure moment to moment?

Answer 6

arterioles(resistance), postcapillary venules (capacitance vessels), heart (altering pump output), kidney (regulating intravascular volume)

Question 7

What are the 4 types of antihypertensive agents?

Answer 7

sympathoplegic agents, direct vasodilators, angiotensin blocking agents, diuretics

Question 8

How do sympathoplegic agents decrease BP?

Answer 8

decrease SVR, inhibit cardiac function, increase venous pooling

Question 9

How do direct vasodilators decrease BP?

Answer 9

relaxing vascular smooth muscle therefore dilating resistance vessels and increasing capacitance a bit as well

Question 10

How do angiotensin blockers decrease BP?

Answer 10

decreased PVR

Question 11

How do diuretics decrease BP?

Answer 11

depleting the body of sodium and reducing blood volume. used mild/moderate HTN and in conjunction with other drugs for more severe HTN.

Question 12

What 3 ways does Calcium affect peripheral vessel diameter?

Answer 12

Stimulate beta-2, block alpha-1, nitric oxide

Question 13

What does stimulating beta-2 do?

Answer 13

g-protein-adenylate cyclase-increase cAMP: vasodilation because decreased intracellular Ca

Question 14

What does blocking alpha-1 do?

Answer 14

g-protein-phospholipase C, decrease Calcium, decrease IP3, decrease DAG: decreased intracellular Ca causes vasodilation

Question 15

What does nitric oxide do?

Answer 15

chemical messenger in many biologic systems, modulator of CV tone (smooth muscle relaxant), platelet regulation/aggregation, NT function in CNS

Question 16

Where is nitric oxide formed?

Answer 16

endothelium

Question 17

What is the effector for nitric oxide?

Answer 17

guanylate cyclase: increases cGMP

Question 18

What does increased cGMP do?

Answer 18

decreases intracellular calcium and causes vasodilation

Question 19

How is intracellular calcium decreased with Nitric oxide?

Answer 19

decreased calcium entry into the cell and increased uptake by sarcoplasmic reticulum

Question 20

What is nitric oxide dependent on?

Answer 20

calcium and calmodulin

Question 21

What type NOS is flow dependent or receptor dependent?

Answer 21

type 3, cNOS

Question 22

What type NOS is produced by inflammation?

Answer 22

type 2, iNOS

Question 23

What are the NT that cause receptor stimulated NOS?

Answer 23

ACh, substance P, serotonin, bradykinin, thrombin, stress

Question 24

Does nitric have long or short half life?

Answer 24

short, binds to heme-based proteins

Question 25

What is NO approved for in US?

Answer 25

only pediatric lung injury

Question 26

What are the off label uses of NO?

Answer 26

severe PHTN, transplant, ARDS

Question 27

True/false, inhaled NO only affects pulmonary circulation.

Answer 27

True, not diffused systemically

Question 28

What is increased as NO combines with Hgb?

Answer 28

methemoglobin levels, can change proportion of iron in Hgb

Question 29

How many cyanide molecules are released by Nipride?

Answer 29

5

Question 30

What limits the conversion of cyanide to thiocyanate?

Answer 30

temperature. hypothermia delays conversion.

Question 31

What is hypoxic pulmonary vasoconstriction (HPV)?

Answer 31

local reaction in response to reduction in alveolar oxygen tension, selectively increases pulmonary vascular resistance in poorly vent areas to minimize shunt flow, protective mechanism during atelectasis or one-lung ventilation. Nipride inhibits HPV.

Question 32

What's the major side effect of Nipride and its s/s?

Answer 32

cyanide toxicity: increased mixed venous O2, metabolic acidosis, CNS dysfunction, tachyphylaxis, cardiac arrhythmia

Question 33

What is the treatment for cyanide toxicity?

Answer 33

shut off nipride drip and use 100% O2, sodium bicarb, thiosulfate 150mg/kg to help convert to thiocyanate, sodium nitrate, B12

Question 34

What are the signs of thiocyanate toxicity?

Answer 34

slow clearance...3-7 days. fatigue, nausea, vomiting, CNS, hypothyroid, vague.

Question 35

What is the treatment of thiocyanate toxicity?

Answer 35

dialysis

Question 36

Is isosorbide dinitrate subject to first pass?

Answer 36

No

Question 37

What is isosorbide dinitrate used for?

Answer 37

angina, post CABG

Question 38

What is the metabolite of isosorbide dinitrate?

Answer 38

isosorbide mononitrate (more active)

Question 39

What happens with acute admin of isosorbide dinitrate?

Answer 39

orthostatic hypotension