pharmacology of hypertension

Question 1

what are some examples of angiotensin converting enzyme inhibitors

Answer 1

ramipril
lisinopril
perindopril

Question 2

what is the primary mechanism of action of ACEi

Answer 2

inhibit ace

prevent conversion of angiotensin 1 to 2

Question 3

what are the main side effects of ACEi

Answer 3

cough
hypotension
hyperkalaemia
foetal injury - AVOID IN PREGNANT WOMEN
can cause renal failure in patients with renal artery stenosis
can cause urticaria/angioedema

Question 4

extra info on acei

Answer 4

most (not linsinopril) - are pro drugs. require hepatic activation to generate active metabolites required for therapeutic effects.
eGFR and serum k+ must be regularly monitored.

Question 5

what are some examples of ccbs

Answer 5

amlodipine

felodipine

Question 6

what is the mechanism of action of ccb

Answer 6

block l type calcium channels predominantly on vascular smooth muscle. results in decrease in calcium influx - with downstream inhibition of myosin in light chain kinase and prevention of cross-bridge formation. resultant vasodilation reduces peripheral resistance

Question 7

primary target of calcium channel blockers

Answer 7

l type calcium channel

Question 8

what are some side effects of ccbs

Answer 8

ankle oedema
constipation
palpitations
flushing/headaches

Question 9

extra info on ccbs

Answer 9

dihydropyridine type calcium channel blockers demonstrate higher degree of vascular selectivity

Question 10

what are some examples of thiazide/ thiazide like diuretics

Answer 10

bendroflumethiazide (thiazide)

indapamide (thiazide like)

Question 11

what is the mechanism of action of thiazide/thiazide like diuretics

Answer 11

block na+ cl- co transporter in distal collecting tube
therefore na+ and cl- reabsorption in inhibited. osmolarity of tubular fluid increases, decreasing osmotic gradient for water reabsorption in collecting duct

Question 12

what is the target of thiazide or thiazide like diuretics

Answer 12

sodium chloride cotransporter

Question 13

what are the side effects on thiazides/thiazide like diuretics

Answer 13

hypokalaemia
hyponatremia
metabolic alkalosis - increased hydrogen ion excretion
hypercalcaemia
hyperglycaemia - from hyperpolarised pancreatic beta cells
hyperuricemia

Question 14

extra info on thiazide and thiazide diuretics

Answer 14

both lose their diuretic effects within 1-2 weeks of treatment. continuing anti - hypertensive action appears to be due to vasodilating properties

Question 15

what are the examples of angiotensin receptor blocker

Answer 15

losartan
irbesartan
candesartan

Question 16

what is mechanism of action of arbs

Answer 16

act us non competitive antagonists at at1 receptors - found on kidneys and vasculature

Question 17

what is the target of arbs

Answer 17

angiotensin 1

Question 18

what are the side effects of arbs

Answer 18

hypotension
hyperkalaemia -
foetal injury - AVOID IN PREGNANT WOMEN
renal failure in patients with renal artery stenosis

Question 19

extra info on arbs

Answer 19

most trials indicate that they are not as effective as acei

losartan and candesartan - - require hepatic activation to generate active metabolites required for therapeutic effects

Question 20

what is clearance

Answer 20

measure of ability of body to eliminate a drug, may occur liver, kidney and other organs

Question 21

what is elimination half life

Answer 21

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

Question 22

what is the time to peak plasma levels

Answer 22

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

Question 23

why does the diuretic effect of thiazides only last for 1-2 weeks

Answer 23

kidney becomes tolerant to diuretics because there is a rebound activation of renin angiotensin system which counteracts diuretic effect due to increasing na reabsorption
* continuing hypertensive effect is due to further vasodilating action