Pharmacology of Hypertension

Question 1

What are the 3 main examples of Angiotensin converting enzyme inhibitors?

Answer 1

• Ramipril
• Lisinopril
• Perindopril

Question 2

What is the primary mechanism of action of Angiotensin converting enzyme inhibitiors?

Answer 2

• inhibits the angiotensin converting enzyme

- prevents the conversion of angiotensin I to angiotensin II by ACE.

Question 3

What is the main drug target of ACE inhibitors?

Answer 3

Angiotensin Converting Enzyme (ACE)

Question 4

What are the main side effects of ACE inhibitors?

Answer 4

• cough
• hypotension
• hyperkalaemia (K+ supplemetation or K+ sparing diuretics to treat)
• foetal injury
• renal failure (in those with renal artery stenosis)
• urticaria
• angioedema

Question 5

What does pro-drug mean?

Answer 5

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

Question 6

Which ACE inhibitors are pro-drugs?

Answer 6

most ACE inhibitors except: Lisinopril

Question 7

What must be regularly monitored while taking ACE inhibitors?

Answer 7

eGFR and serum potassium

Question 8

Which is more effective, angiotensin receptor blockers or ACE inhibitors as anti-hypertensive agents?

Answer 8

ACE inhibitors

Question 9

What are some examples of pro-drugs?

Answer 9

• Losartan

- Candesartan

Question 10

What are some examples of calcium channel blockers?

Answer 10

• Amlodipine

- Felodipine

Question 11

What is the primary mechanism of action of calcium channel blockers?

Answer 11

• block L-type calcium channels (on vascular smooth muscle)
• decreased calcium influx
• downstream inhibition of myosin light chain kinase and prevention of cross-bridge formation
• resulting vasodilation reduced peripheral resistance

Question 12

What is the primary drug target of calcium channel blockers?

Answer 12

L-type calcium channel

Question 13

What are the side effects of calcium channel blockers?

Answer 13

• ankle oedema
• constipation
• palpitations
• flushing
• headaches

Question 14

Which type of calcium channel blockers show higher vascular selectivity?

Answer 14

Dihydropyridine type calcium channel blockers

Question 15

What are examples of Thiazide or Thiazide-like diuretics?

Answer 15

Thiazide:
Bendro-flumethiazide
Thiazide-like:
Indapamide

Question 16

What is the mechanism of action of Thiazide/Thiazide-like diuretics?

Answer 16

• block the Na+/Cl- co-transporter in the early distal convoluted tubule
• reducing Na+ and Cl- reabsorption
• osmolarity of the tubular fluid increases, decreasing the osmotic gradient for water reabsorption in the collecting duct.

Question 17

What is the primary drug target of Thiazide/Thiazide-like diuretics?

Answer 17

Na+/Cl- co-transporter

Question 18

What are the side effects of Thiazide/Thiazide-like diuretics?

Answer 18

• hypokalaemia
• hyponatremia
• metabolic alkalosis (increased H+ excretion)
• hypercalcaemia
• hyperglycemia (hyperpolarised pancreatic beta cells)
• hyperuricemia

Question 19

How long do the effects of Thiazide and Thiazide-like duiretics last?

Answer 19

• lose their diuretic effects in 1-2 weeks of treatment
• continuing anti-hypertensive action appears to be due to vasodilating properties (more pronounced for Thiazide-like diuretics)

Question 20

What are some examples of Angiotensin receptor blockers?

Answer 20

• Losartan
• Irbesartan
• Candesartan

Question 21

What is the mechanism of action of angiotensin receptor blockers?

Answer 21

insurmontable (non-competitive) antagonists at AT1 receptors (found on kidneys and vasculature)

Question 22

What is the drug target of angiotensin receptor blockers?

Answer 22

angiotensin (AT1) receptor

Question 23

What are the side effects of angiotensin receptor blockers?

Answer 23

• hypotension
• hyperkalaemia (care with K+ supplements or K+ sparing diuretics)
• foetal injury
• renal failure (in those with renal artery stenosis)

Question 24

What is the Q-risk?

Answer 24

risk of a specific person having a stroke or a heart attack.

Question 25

When hypertensive, when should drug treatment start?

Answer 25

• target organ damage
• CVD (or a 10 year risk>10%)
• Renal disease
• Diabetes

Question 26

What is the impact of calcium channel blockers on the heart?

Answer 26

• decreased muscular contraction
• educed cardiac contraction
• reduced cardiac output
• educed blood pressure

Question 27

What is the impact of calcium channel blockers on blood vessels?

Answer 27

• decreased muscular contraction
• reduced vasoconstriction
• reduced peripheral resistance
• reduced blood pressure

Question 28

What is the definition of clearance?

Answer 28

measure of the ability of a body to eliminate a drug

may occur as a result of processes in the heart, liver and kidney

Question 29

What is the definition of elimination half-life?

Answer 29

length of time required for the concentration of particular drug to decrease to half it’s starting dose in the body

Question 30

what does: time to peak plasma levels mean?

Answer 30

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

Question 31

What is the difference between felodipine and amlodipine?

Answer 31

felodipine causes a decrease in both systolic and diastolic blood pressure and reflex tachycardia.
amlodipine has a longer half-life and a slow onset.

Question 32

What are the main effects of ACE inhibitors?

Answer 32

• vasoconstriction
• salt and water retention
• aldosterone secretion

Question 33

When are angiotensin receptor blockers prefered over ACE inhibitors?

Answer 33

in those of african or caribbean descent

Question 34

What are the main effects of Thiazide-like diuretics?

Answer 34

• decrease blood volume
• decrease venous return
• decrease cardiac output
• Na+ and H2O loss

Question 35

Why do the effects of Thiazide/Thiazide-like diuretics stop after 2 weeks?

Answer 35

kidney becomes tolerant to the diuretics due to rebound activation of the renin-angiotensin system, counteracting the diuretic effect by increasing Na+ reabsorption.