Hypertension, Hypotension and Therapeutic Intervention

Question 1

Define hypertension.

Answer 1

> = 140mmHg systolic pressure or >= 90mmHg diastolic pressure.

Question 2

What is the equation for arterial blood pressure?

Answer 2

ABP = CO * TPR

Question 3

List 3 systems that maintain blood pressure.

Answer 3

1 - Baroreceptor reflex.

2 - Autonomic nervous system.

3 - Renin-angiotensin-aldosterone system.

Question 4

List 3 factors that determine drug choice for hypertension treatment.

Answer 4

1 - Age.

2 - Genetics.

3 - Comorbidities.

Question 5

List 2 examples of ACE inhibitors.

Answer 5

1 - Lisinopril.

2 - Enalapril.

Question 6

Describe the mechanism of action of ACE inhibitors.

Answer 6

• Inhibition of ACE decreases angiotensin II, decreasing CO and TPR.
• ACE inhibitors also decrease degradation of vasodilator kinins, e.g. bradykinin.

Question 7

Give an example of a side effect of ACE inhibitors.

What might cause this side effect?

Answer 7

• Dry cough.

- Due to decreased degradation of kinins in the lungs.

Question 8

Give an example of a drug that is contraindicated with ACE inhibitors.

Why is this drugs contraindicated with ACE inhibitors?

Answer 8

• Diuretics.

- Causes sudden, severe hypotension if taken with diuretics.

Question 9

When are ACE inhibitors used clinically for hypertensive patients?

Answer 9

They are the first line treatment for uncomplicated, mild hypertension in younger patients.

Question 10

List 2 angiotensin II type 1 receptor (AT1 receptor) antagonists.

Answer 10

1 - Losartan.

2 - Irbesartan.

Question 11

Describe the mechanism of action of angiotensin II type 1 receptor (AT1 receptor) antagonists.

Answer 11

Decreases vasoconstriction by angiotensin II, decreasing CO and TPR.

Question 12

When are ACE inhibitors used clinically for hypertensive patients?

Answer 12

If ACE inhibitors are not tolerated.

Question 13

Give an example of a calcium channel blocker.

Answer 13

Amlodipine.

Question 14

Describe the mechanism of action of calcium channel blockers.

Answer 14

Decreases contractility of vascular muscle, decreasing TPR.

Question 15

List 2 side effects of calcium channel blockers.

Answer 15

1 - Heart dysrhythmias.

2 - Decreased GIT activity.

Question 16

When are calcium channel blockers used clinically for hypertensive patients?

Answer 16

They are the first line treatment for uncomplicated, mild hypertension.

Question 17

Which diuretics are best for treating hypertension?

Answer 17

Thiazide / thiazide-like diuretics (better than loop diuretics).

Question 18

Describe the mechanism of action of diuretics for treatment of hypertension

Answer 18

Biphasic mechanism:

• Initially, increases water and Na+ excretion from the kidneys, decreasing blood volume and therefore cardiac output.
• In the later phase, cause arterial dilation due to a decrease in intracellular Ca2+, decreasing TPR.
• NB compensation occurs to restore blood volume after initial phase.

Question 19

Give an example of an unwanted effect of diuretics as a treatment for hypertension.

Answer 19

Hypokalaemia.

Question 20

When are diuretics used clinically for hypertensive patients?

Answer 20

They are the first line treatment for uncomplicated, mild hypertension.

Question 21

List 2 beta antagonists.

For each drug, state the subclass of beta antagonists to which they bind.

Answer 21

1 - Propranolol (beta 1 and 2).

2 - Atenolol (beta 1).

Question 22

Describe the mechanism of action of beta antagonists.

Answer 22

1 - Decreases heart rate and contractility, decreasing cardiac output (beta 1 receptors).

2 - Decrease renin secretion, resulting in decreased blood angiotensin II, reducing CO and TPR.

Question 23

List 2 side effects of beta antagonists.

Answer 23

1 - Bronchospasm (beta 2 receptors).

2 - Exercise intolerance.

Question 24

When are beta antagonists used clinically for hypertensive patients?

Answer 24

Recent guidance is to avoid as beta blocker use is associated with development of type 2 diabetes.

Question 25

List 2 alpha 1 antagonists.

Answer 25

1 - Prazosin.

2 - Doxazosin.

Question 26

Describe the mechanism of action of alpha 1 antagonists.

Answer 26

Decreases vasoconstriction, decreasing CO and TPR.

Question 27

Give an example of a side effect of alpha 1 antagonists.

Answer 27

Postural hypotension.

Question 28

When are alpha antagonists used clinically for hypertensive patients?

Answer 28

For patients with severe hypertension.

Question 29

List all of the drug classes mentioned in this lecture and group them according to the NICE flowchart guidance for drug selection.

Answer 29

A:

1 - ACE inhibitoes.

2 - AT1 receptor antagonists.

B:

1 - Beta antagonists.

C:

1 - Calcium channel blockers.

D:

1 - Diuretics.

Question 30

List 3 causes of hypotension.

Answer 30

1 - Haemorrhage.

2 - Burns.

3 - Shock.

Question 31

Give an example of a drug treatment for hypotension.

Answer 31

Sympathomimetics, e.g. adrenaline.

Question 32

Describe the mechanism of action of adrenaline for treatment of hypotension.

Answer 32

Adrenaline increases cardiac output.

Question 33

In reality, how is hypotension treated?

Answer 33

By replacing lost fluid (not with drug interventions).