Hypertension

Question 1

What is the drug target for ACE Inhibitors?

Answer 1

Angiotensin converting enzyme

Question 2

What is the mechanism of action for ACE Inhibitors?

Answer 2

Inhibit the angiotensin converting
enzyme.
Prevent the conversion of
angiotensin I to angiotensin II
by ACE.

Question 3

What are the side effects of Ace Inhibitors?

Answer 3

Cough

Hypotension

Hyperkalaemia (care with K+ supplements or K+-sparing diuretics)

Foetal Injury (AVOID IN PREGNANT WOMEN)

Renal failure (in patients with renal artery stenosis)-

Urticaria/Angioedema

Question 4

Why are ACE inhibitors considered pro drugs?

Answer 4

They require hepatic activation to generate the active metabolites required for therapeutic effects.

Question 5

What must be regularly monitored when prescribing ACE inhibitors?

Answer 5

eGFR and serum potassium must be regularly monitored when prescribing ACE inhibitors.

Question 6

What are some examples of ACE inhibitors?

Answer 6

Ramipril
Lisinopril
Perindopril

Question 7

What are some examples of calcium channel blockers?

Answer 7

Amlodipine
Felodipine

Question 8

What are the side effects of CCB?

Answer 8

Ankle oedema
Constipation
Palpitations
Flushing/Headaches

Question 9

What is the mechanism of action of CCBs?

Answer 9

Block L-type calcium channels – predominantly on vascular smooth muscle. This results in a decrease in calcium influx, with downstream inhibition of myosin light chain kinase and prevention of cross-bridge formation. The resultant vasodilation reduces peripheral resistance.

Question 10

What is the drug target of CCBs?

Answer 10

L-type calcium channel

Question 11

Which type of CCBs demonstrate a higher degree of vascular selectivity?

Answer 11

Dihydropyridine type calcium channel blockers demonstrate a higher degree of vascular selectivity

Question 12

What is the mechanism of action of Thiazide?

Answer 12

They block the 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 the osmotic gradient for water reabsorption in the collecting duct.

Question 13

What is the site of action for Thiazide?

Answer 13

Sodium/chloride
co-transporter

Question 14

What is the mechanism of action of Angiotensin receptor blockers?

Answer 14

These agents act as insurmountable (i.e. non-competitive) antagonists at AT1 receptor (found on kidneys and on the vasculature)

Question 15

What are the side effects of Angiotensin-receptor blockers?

Answer 15

Hypotension

Hyperkalaemia (care with K+ supplements or K+-sparing diuretics)

Foetal Injury (AVOID IN PREGNANT WOMEN)

Renal failure (in patients with renal artery stenosis)-

Question 16

What are some examples of angiotensin receptor blockers?

Answer 16

Losartan
Irbesartan
Candesartan

Question 17

What is the clearance of a drug?

Answer 17

Clearance is the measure of the ability of the body to eliminate a drug. Clearance by means of various organs of elimination is additive. Elimination of drug may occur as a result of processes that occur in the liver, kidney, and other organs.

Question 18

What is the elimination half life of a drug?

Answer 18

Elimination half-life is the length of time required for the concentration of a particular drug to decreasetohalf of itsstarting dose in the body.

Question 19

What is the time to peak plasma levels?

Answer 19

Time to peak concentration is the time required for a drug to reach peak concentration in plasma. The faster the absorption rate, the lower is the time to peak plasma concentration.

Question 20

Who are ARB’s for?

Answer 20

ARBs for patients of African or Caribbean descent

Question 21

Why are ACEi used ahead of ARB’s?

Answer 21

ACE inhibitors are typically used ahead of angiotensin 2 receptor blockers (partly due to cost/partly due to evidence that ACE Is are more effective).

Question 22

What are the effects of Thiazide-like diuretics?

Answer 22

Decrease blood volume
Decrease venous return
Decrease cardiac output

Question 23

how long do the diuretic effects?

Answer 23

The diuretic effect of thiazides only lasts for 1-2 weeks. - The kidney becomes tolerant to the diuretics because there is a rebound activation of the renin angiotensin system which counteracts the diuretic effect due to increasing sodium reabsorption.