Treating hypertension

Question 1

What are some complications of hypertension?

Answer 1

Stroke
Kidney disease
Diabetes

Question 2

What is the difference btw primary and secondary hypertension?

Answer 2

Primary hypertension has no obvious cause and/or is not related to any other diseases.

Question 3

What are some causes of secondary hypertension?

Answer 3

Renal/renal disease
Endocrine disease (Cushing’s)
Iatrogenic - NSAIDS/hormonal oral contraceptive.

Question 4

What is the equation for BP?

Answer 4

BP = CO x TPR

Question 5

What is the equation for CO?

Answer 5

CO = HR x SV

Question 6

What are 4 drug types usually used to control blood pressure?

Answer 6

ACE inhibitors
Angiotensin II receptor blockers
Calcium channel blocker
Diuretics

Question 7

Name 2 ACE inhibitors

Answer 7

Captopril

Enalapril

Question 8

How do ACE inhibitors work?

Answer 8

They inhibit angiotensin I converting enzyme, to stop the formation of angiotensin II which has effects on the renal system which increase H20 absorption, causes vasoconstriction, increases aldosterone production.

However due to there being no angiotensin II, less Na and water is reabsorbed, less aldosterone produced and less vasoconstriction occurs meaning more water lost via urine - lowering blood volume and therefore reducing blood pressure.

Question 9

What is a side effect of ACE inhibitors?

Answer 9

Hyperkalemia

Cough due to inhibition of bradykinin breakdown.

Question 10

What is an example of an ATII receptor blocker?

Answer 10

Losartan

Question 11

What is a benefit of using an ATII blocker compared to an ACE inhibitor?

Answer 11

No cough

Better tolerated

Question 12

What are some side effects of ATII antagonists

Answer 12

Hyperkalaemia

Question 13

What are some calcium channel blockers which we would use to cause peripheral vasodilation?

Answer 13

Dihydropyridines such as nifedipine - they are more selective for the periphery which makes them better for lowering blood pressures.

They also reduce preload of the heart (filling pressure).

Question 14

What are some effects of using dihydropyridines (such as nifedipine)

Answer 14

Peripheral oedema (due to vasodilation)
Dizziness
Constipation (lack of gut smooth muscle contraction)
May worsen GORD (due to relaxation of the smooth muscle in the lower oesophageal sphincter).

Question 15

What are the different classes of diuretics?

Answer 15

Loop agents - such as furosemide
- potent - up to 30% of filtered Na

Thiazide - hydrochlorothiazide

• mild diuretic effect
• direct vasoconstrictor

K+ sparing - spironolactone

• weak diuretic
• useful to control K+ loss due to other diuretics.

Question 16

What is the method of action of thiazides?

Answer 16

Blocks Na+-Cl- symporter in the first part of DCT, leading to an increase Na+ load and therefore Increased water content in the nephron of the kidney.

Also had a vasodilation effect therefore more water filtered into the nephron.

Question 17

When are B blockers useful in treating hypertension?

Answer 17

B blockers are useful in hypertension where ACD has failed to achieve sufficient BP control.

• b1 selective antagonists decrease cardiac output and also decrease renin secretion.

Question 18

Name a B1- selective B blocker?

Answer 18

atenolol

Question 19

Name a a1 selective B blocker?

Answer 19

Carvedilol - improves coronary perfusion.

Question 20

What are some side effects of B blockers

Answer 20

constipation

indigestion

hypotension

Question 21

Give an example of an alpha blocker?

Answer 21

Prazosin

Doxazosin

Question 22

When would we use alpha blockers to treat bp?

Answer 22

When bp has not been adequately controlled by ACD.

Question 23

Aldosterone antagonism method.

Answer 23

Studies show that primary aldosteronism is common in patients with resistive hypertension.

Spironolactone can help with resistant hypertension.

Blocks the effect of aldosterone at DCT.

Question 24

What are some side effects of spironolactone.

Answer 24

hyperkalemia - anti androgenic effect

Question 25

When would we use A2 agonists?

Answer 25

A2 adrenoceptor agonist action inhibits NE release - primary act via SNS

Not very selective due to CNS effects

Reserved for extreme resistant hypertension

Question 26

When can’t we use direct vasodilators to treat hypertension?

Answer 26

pregnancy

Question 27

What are some direct vasodilators we can use to treat hypertension?

Answer 27

NO donors (glyceroltrinitrate)
Hydralazine
K+ channel activators.