(THER) Vasoactive Peptides

Question 1

Captopril MOA and Route

Answer 1

MOA: Ace Inhibitor

Route: Oral

Question 2

Captopril Indications and Side Effects

Answer 2

Ind: Hypertension

SE: severe stomach pain; chest pain; allergic reaction

Question 3

Enalapril MOA and Route

Answer 3

MOA: ACE inhibitor

Route: Oral

Question 4

Enalapril Indications and Side Effects

Answer 4

Ind: Hypertension

SE: Hypotension; severe stomach pain

Question 5

Losartan MOA and Route

Answer 5

MOA: Angiotensin receptor inhibitor

Route: Oral

Question 6

Losartan Indications and Side Effects

Answer 6

Ind: Hypertension

SE: Diarrhea; insomnia; nasal congestion

Question 7

Valsartan MOA and Route

Answer 7

MOA: Angiotensin receptor inhibitor

Route: Oral

Question 8

Valsartan Indications and Side Effects

Answer 8

Ind: Hypertension

SE: Stomach pain; nausea

Question 9

Icatibant MOA and Route

Answer 9

MOA: Bradykinin receptor inhibitor

Route: Oral

Question 10

Icatibant Indications and Side Effects

Answer 10

Ind: Inflammation

SE: stomach pain; nausea

Question 11

Desmopressin (DDAVP) MOA and Route

Answer 11

MOA: Vasopressin analogue; Increases the factor VIII activity of patients with mild hemophilia and VWD.

Route: IV

Question 12

Desmopressin Indications and Side Effects

Answer 12

Ind: Bleeding (Initially developed for Pt. w/ diabetes insipidus)

SE: Headache; stomach pain; nausea

Question 13

Bosentan MOA and Route

Answer 13

MOA: Endothelin receptor inhibitor

Route: Oral/ IV

Question 14

Bosentan Indications and Side Effects

Answer 14

Ind: Pulmonary arterial hypertension

SE: Liver problems; stomach pain; nausea

Question 15

Name the (3) most important vasoactive peptides

Answer 15

1. Angiotensins (I, II and III)
2. Bradykinin/related kinins
3. Endothelins

Question 16

Which of the angiotensins is the active form ( I, II, or III?)

Answer 16

Angiotensin II is the only active form and produces profound vasoconstriction and other pharmacologic responses

Question 17

Angiotensinogen

Answer 17

A circulating protein from which renin cleaves to form angiotensin I

Question 18

What is the purpose of ACE and what are the other names associated with it?

Answer 18

It catalyzes the conversion of angiotensin I into angiotensin II

aka Peptidyl dipeptidase or Kininase II

Question 19

Pharmacologic actions of Angiotensin II

What can happen if there is excessive production?

Answer 19

Exerts profound effects in the regulation (constriction) of vascular tone, fluid and electrolyte balance.

Excessive production results in hypertension and disorders of hemodynamics.

Question 20

What are the 3 types of drugs which block the formation/action of angiotensin II?

Answer 20

1. Drugs blocking renin secretion/action
2. ACE inhibitors
3. Angiotensin receptor blockers

Question 21

In addition to blocking the formation of angiotensin II, ACE inhibitors also function to block…

What can this lead to?

Answer 21

Bradykinin metabolism

This can lead to a signficant hypotensive effect, which has been reported as a severe side effect.

Question 22

Name the 2 ACE inhibitors used clinically

Answer 22

1. Captopril
2. Enalapril

Question 23

Do angiotensin receptor antagonists have any effect on the actions of ACE?

Answer 23

No

Question 24

Can angiotensin antagonists be given to a hypertensive patient with sepsis?

Answer 24

No. Increases in bradykinin levels would lead to increased hypotension.

Question 25

Describe the steps which lead to Bradykinin formation

Answer 25

HMW kininogen is converted to Bradykinin via **Plasma kallikrein**.

Question 26

What is responsible for the degradation of Bradykinin to inactive fragments

Answer 26

Kininases I and II

Question 27

Activated kallikrein can generate ________ and cause profound \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_

Answer 27

Kinins; hypotension

Question 28

Why do many patients with consumption coagulapathy (DIC) develop hypotension?

Answer 28

Due to increased kallikrein production

Question 29

HMWK

Answer 29

High Molecular Weight Kininogen It is cleaved by plasma kallikrein to generate bradykinin

Question 30

What is the role of Kinins in inflammation and pain

Answer 30

Kinins promote rubor, calor, dolar, and tumor.

Question 31

Aspirin and bradykinin

Answer 31

Aspirin is known to block the algesic effects of prostaglandins generated by bradykinin

Question 32

General effects of naturiuretic peptides

Answer 32

Diuretic and vasorelaxant

Question 33

What are Kallikreins?

Answer 33

Kallikreins are glycoprotein enzymes produced in the liver as prekallikreins and are present throughout the body.

Question 34

Fletcher factor? What factor can activate it?

Answer 34

Plasmatic _prekallikrein_. Promotes Coagulation process via intrinsic system. Can be activated by factor XIIa (Hageman factor).

Question 35

Name the two different types of kininogens present in the plasma?

Answer 35

Low molecular weight kininogen and HMWK

Question 36

Compare the potency of Kinins to the potency of histamine

Answer 36

Kinins are 10 times more potent than histamine

Question 37

What do kinins stimulate the release of?

Answer 37

NO and prostaglandins

Question 38

How can kinins lead to edema?

Answer 38

Kinins promote water and solution passage from the blood to extracellular fluid

Question 39

What are the 2 types of receptors which mediate the biologic actions of kinins? What is the function of each?

Answer 39

**Two receptor types:** B1: predominant receptor for biologic responses of kinins B2: drugs that block the actions of bradykinin target these receptors

Question 40

Main function of **Trilats** (omapatrilat, sampartilat and fasidotrilat) (3)

Answer 40

1. Enhance vasodilation 2. Reduce Vasoconstriction 3. Increase Sodium excretion **Enhance levels of natriuretic peptides**