Pharmacology of hypertension

Question 1

What is the drug target for ACE inhibitors?

Answer 1

Angiotensin converting enzyme

Question 2

List some example of ACE inhibitors

Answer 2

Ramipril, Lisinopril, Perindopril

Question 3

Outline the primary mechanism of action of ACE inhibitors

Answer 3

Inhibit the angiotensin converting enzyme preventing the conversion of angiotensin1 to angiotensin2 by ACE

Question 4

What are the main side effects associated with the use of ACE inhibitors?

Answer 4

Cough, hypotension, hyperkalaemia, foetal injury, renal failure, angioedema

Question 5

Which ACE inhibitor is NOT a pro-drug?

Answer 5

Lisinopril

Question 6

Most ACE inhibitors are pro-drugs, what is required for their activation?

Answer 6

Require hepatic activation to generate the active metabolites required for therapeutic effects

Question 7

When prescribing ACE inhibitors what must be regularly monitored in the patient?

Answer 7

eGFR and serum potassium

Question 8

List two examples of calcium channel blockers

Answer 8

Amlodipine and Felodipine

Question 9

What are the drug targets for Calcium channel blockers?

Answer 9

L-type calcium channels

Question 10

Outline the primary mechanism of action of Calcium channel blockers

Answer 10

Block L-type calcium channels on vascular smooth muscle, resulting in a decrease in calcium influx preventing muscle contraction. The resultant vasodilation reduces peripheral resistance

Question 11

What are the main side effects associated with use of calcium channel blockers?

Answer 11

Ankle oedema, constipation, palpitations, flushing, headaches

Question 12

What is the drug target for Thiazide or Thiazide diuretics?

Answer 12

Sodium/chloride cotransporter

Question 13

Outline the primary mechanism of action of Thiazide or Thiazide-like diuretics

Answer 13

Block Na+/Cl- co-transporter in the early DCT therefore Na+ and Cl- reabsorption is inhibited. As a result the osmolarity of the tubular fluid increases, decreasing osmotic gradient for water reabsorption in the collecting duct

Question 14

What are the main side effects associated with the use of Thiazide or Thiazide-like diuretics?

Answer 14

Hypokalaemia, hyponatraemia, metabolic alkalosis, hypercalcaemia, hyperglycaemia, hyperuricemia

Question 15

How do Thiazide or thiazide-like diuretics cause hyperglycaemia?

Answer 15

Cause hyperpolarisation of pancreatic beta-cells

Question 16

After how long do Thiazide or thiazide-like diuretics lose their diuretic affects?

Answer 16

Within 1-2 weeks of treatment.

Question 17

List three examples of Angiotensin receptor blockers

Answer 17

Losartan, Irbesartan, Candesartan

Question 18

Outline the primary mechanism of action of Angiotensin receptor blockers

Answer 18

Act as non-competitive anatomists at AT1 receptor found on kidneys and on the vasculature

Question 19

What are the main side effects associated with the use of angiotensin receptor blockers

Answer 19

Hypotension, hyperkalaemia, foetal injury and renal failure

Question 20

When are Angiotensin receptor blockers and ACE inhibitors likely to cause renal failure (what patients should we avoid prescribing them to) ?

Answer 20

Patients with renal artery stenosis

Question 21

What are more affective as anti-hypertensive agents: Angiotensin receptor blockers or ACE inhibitors?

Answer 21

ACE inhibitors

Question 22

What classes as stage 1 hypertension?

Answer 22

BP of 135/85 - 149/94

Question 23

When would you start drug treatment for someone with stage 1 hypertension?

Answer 23

If there is: organ damage, CVD, Renal disease or diabetes

Question 24

What classes as stage 2 hypertension?

Answer 24

BP of 150/95 or more

Question 25

What are the therapeutic objectives when treating hypertension?

Answer 25

Reasonable blood pressure goals and reducing cardiovascular risk

Question 26

What is meant by the term ‘drug clearance’ ?

Answer 26

Clearance is the measure of ability of the body to clear a drug

Question 27

What is meant by the term ‘elimination half-life’ ?

Answer 27

The length of time required for the concentration of a particular drug to decrease to half of its starting dose in the body

Question 28

What is meant by the term ‘time to peak plasma levels’ ?

Answer 28

Time required for a drug to reach peak concentration in plasma

Question 29

Why might ACE inhibitors have a negative effect on eGFR and sodium potassium?

Answer 29

Angiotensin 2 is the major determinant of efferent vasoconstriction, it helps to maintain GFR when renal perfusion is low therefore blocking the action of Ang2 can cause acute renal failure

Question 30

What are the main overall effects of thiazide-like diuretics?

Answer 30

Na+ and water loss from tubule lumen, decreased blood volume, decreased venous return and decreased cardiac output