pharmacology of hypertension

Question 1

ACEi examples

Answer 1

Ramipril

Lisinopril

Perindopril

Question 2

mechanism of action of ACEi

Answer 2

nhibit the angiotensin converting

enzyme.

Prevent the conversion of

angiotensin I to angiotensin II

by ACE.

Question 3

What must be carefully monitored when prescribing ACEi

Answer 3

eGFR and serum potassium

Question 4

6 side effects of ACEi

Answer 4

1) cough
2) hypotension
3) hyperkalaemia (be careful with potassium supplements and potassium sparing diuretics)
4) foetal injury (don’t give to pregnany women)
5) renal failure (in renal artery stenosis)
6) urticario or angioedema

Question 5

What do ACE inhibitors need to have a therapeutic effect and why

Answer 5

Most ACEi are pro drugs so need hepatic activation to generate active metabolites needed for therapeutic effect

Question 6

Mechanism of action of calcium channel blockers

Answer 6

Blocks L type calcium channels mostly on vascular smooth muscle. Decreased influx of calcium causes inhibition of myosin light chain kinase and prevention of cross bridge formation. So vasodilation occurs decreasing peripheral vascular resistance

Question 7

Target of calcium channel blockers

Answer 7

L type calcium channels

Question 8

Ex of calcium channel blockers

Answer 8

amlodipine. felodipine

Question 9

side effects of calcium channel blockers

Answer 9

ankle oedema
constipation
palpitations
flushing or headaches

Question 10

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

Answer 10

yes

Question 11

Which diuretics cause hypercalcaemia

Answer 11

thiazide diuretics

Question 12

Mechanism of action of thiazide diuretics

Answer 12

Blocks Sodium chloride co transporters in early DCT. so sodium and chloride reabsorption is blocked
This increases osmolality in the tubular fluid, decreasing the osmatic gradient in the collecting duct for water reabsorption

Question 13

Side effects of thiazide diuretics

Answer 13

hypokalaemia 
hyponatraemia 
hypercalcaemia 
hyperuricaemia 
hyperglycaemia (hyperpolarised pancreatic beta cells)

Question 14

Ex of thiazide diuretic

Answer 14

bendro -flu-methiazide

Question 15

Ex of thiazide like diuretic

Answer 15

indapamide

Question 16

Thiazide and thiazide-like diuretics both lose their diuretic effects within 1-2 weeks of treatment.

Answer 16

Thiazide and thiazide-like diuretics both lose their diuretic effects within 1-2 weeks of treatment.

Question 17

Why do thiazides still retain anti hypertensive properties after losing their diuretic effect

Answer 17

Continuing anti-hypertensive action appears to be due to vasodilating properties (these are more pronounced for the thiazide-like diuretics)

Question 18

Ex of ARBs

Answer 18

Losartan

Irbesartan

Candesartan

Question 19

ARB mechanism of action

Answer 19

non competitive antagonist at AT1 receptor (on kidneys and vasculature)

Question 20

Side effects of ARBs

Answer 20

hypotension
hyperkalaemia (N.B k sparing diuretics and supplements)
foetal injury (don’t give to pregnants)
renal failure (if renal artery stenosis)

Question 21

Are ARBs or ACEi more effective

Answer 21

Most trials indicate that angiotensin receptor blockers are not as effective anti-hypertensive agents as ACE inhibitors.

Question 22

Losartan and candesartan are what type of drugs

Answer 22

Losartan and candesartan are pro-drugs. They require hepatic activation to generate the active metabolites required for therapeutic effects.

Question 23

Def clearance

Answer 23

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 24

Def elimination half life

Answer 24

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 25

Def time to peak plasma levels

Answer 25

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 26

Explain would you see reflex tachycardia in amlodipine or felodipine

Answer 26

amlodipine has a longer half life and a slower onset so you don’t get the reflex tachycardia that you see in felodipine

Question 27

compare felodipine and amplodipine in terms of elimination, and time to reach peak plasma levels

Answer 27

felodipine reaches peak plasma levels quicker and is eliminated quicker