antihypertensive drugs

Question 1

what is hypertension?

Answer 1

high blood pressure. a sustained systolic BP >160mmHg or a sustaained diastolic BP of >100mmHG.

Question 2

action of antihypertensive drugs?

Answer 2

lower blood pressure

Question 3

equation for blood pressure?

Answer 3

cardiac output X total peripheral resistance

Question 4

how can we reduce cardiac output?

Answer 4

reducing heart rate, stroke volume or plasma volume

Question 5

how can we reduce total peripheral resistance?

Answer 5

by dilating arterioles

Question 6

examples of antihypertensive drugs?

Answer 6

diuretics, vasodilators, beta blockers, ACE inhibitors, A-blockers and angiotensin antagonists

Question 7

action of diuretics?

Answer 7

act on the kidneys to increase diuresis; increase Na+ excretion which reduces salt re-absorption from glomerular filtrate - water loss follows - reduced plasma volume - reduced cardiac output

Question 8

what is the functional unit of the kidney?

Answer 8

the nephron - this contains the bowman’s capsule which encloses the glomerulus.

Question 9

where does blood filtration occur?

Answer 9

glomerulus

Question 10

examples of diuretics

Answer 10

loop diuretics and thiazides; e.g. chlorothiazide and bendrofluazide

Question 11

which part of the kidney to thiazides act on?

Answer 11

distal convoluted tubule

Question 12

which part of the kidney do loop diuretics act on?

Answer 12

loop of henle

Question 13

action of thiazides?

Answer 13

reduce blood pressure, inhibit Na+ and Cl- co-transport distal tubule, vasodilation actions, increases renin release

Question 14

describe loop diuretics?

Answer 14

potent, reserved for patients with renal insufficiency, resistant hypertension of heart failure

Question 15

side effects of thiazides?

Answer 15

frequent urination

Question 16

examples of vasodilators?

Answer 16

calcium antagonists, a-blockers, angiotensin antagonists

Question 17

action of vasodilators?

Answer 17

act directly on smooth muscle cells of arteries and arterioles, lower intracellular calcium concentration, cause muscle cell relaxation and vasodilation

Question 18

examples of calcium antagonists?

Answer 18

dihydropyridines, benzothiazepine

Question 19

examples of b-blockers

Answer 19

atenolol, metoprolol

Question 20

action of beta blockers?

Answer 20

bind to and block B1 adrenoreceptors in the heart, blocking the action of noradrenaline released from sympathetic nerves and circulating adrenaline - they decrease force of heart beat and decrease cardiac output

Question 21

side effects of beta blockers?

Answer 21

cold hands, fatigue, provoke asthma attack, heart failure and conduction block in heart

Question 22

examples of ACE inhibitors?

Answer 22

captopril, enalapril, Lisinopril, ramipril

Question 23

action of ACE inhibitors?

Answer 23

prevent the conversion of angiotensin I to angiotensin II which prevents vasoconstriction and stimulates aldosterone secretion, inhibiting salt and h20 excretion

Question 24

side effects of ACE inhibitors?

Answer 24

dry cough, hypotension

Question 25

examples of angiotensin antagonists?

Answer 25

losartan, candesartan, eprosartan, valsartan

Question 26

action of angiotensin antagonists?

Answer 26

block the action of angiotensin II at its receptors, competes for binding to AT receptors

Question 27

what ate the preferred drugs for essential hypertension?

Answer 27

ACE inhibitors, calcium antagonists, thiazides