Hypertension

Question 1

What is the resting BP in hypertension?

Answer 1

SBP > 140mmHg

DBP > 90mmHg

Question 2

Organs that will be damaged by hypertension

Answer 2

heart, brain, retina, kidney, dissecting aortic aneurysm

Question 3

Tissues damaged due to artherosclerosis

Answer 3

Coronary, cerebral vessels, carotids

Question 4

What two broad changes occur in the cardiovascular system in response to hypertension?

Answer 4

Cardiac and vascular hypertrophy

Question 5

Lifestyle changes to treat hypertension?

Answer 5

regular exercise, reduced dietary salt, decreased alcohol, lower weight

Question 6

Groups of commonly used antihypertensive drugs

Answer 6

angiotensin converting enzyme inhibitors and angiotensin antagonists
beta blockers
calcium channel blockers
diuretics (thiazides, loops, K+ sparing)
extras

Question 7

Where does angiotensinogen come from?

Answer 7

liver

Question 8

what converts angiotensinogen into angiotensin I?

Answer 8

renin from juxta-glomerular cells

Question 9

what converts angiotensin I to angiotensin II?

Answer 9

ACE (lungs and elsewhere)

Question 10

What does angiotensin II cause?

Answer 10

vasoconstriction (has direct effect on lumen diameter), aldosterone output, sodium and water retention

Question 11

what converts bradykinin to inactive products?

Answer 11

ACE (lungs and elsewhere)

Question 12

where are angiotensin I and II found?

Answer 12

in the bloodstream

Question 13

What do ACE inhibitors do? -opril, -april

Answer 13

• prevent angiotensin II formation and inhibit bradykinin breakdown, resulting in lower peripheral resistance and sodium and water excretion

Question 14

What are the indications for use of ACE inhibitors?

Answer 14

hypertension, heart failure, preserve renal function in diabetes (diabetic nephropathy)

Question 15

contraindications for ACE inhibitors?

Answer 15

• less effective in patients of African origin
• renal failure if there is also renal artery stenosis
• avoid in pregnancy

Question 16

Common side effects of ACE inhibitors?

Answer 16

cough (from high bradykinin), headache, marked hypotension (start with low dose), hyperkalaemia (beware of K+ supplements or K+ sparing diuretics)

Question 17

infrequent side effects of ACE inhibitors?

Answer 17

rash/itch, taste disturbances, angioedema

Question 18

Example of ACE inhibitor?

Answer 18

perindopril

Question 19

Example of an angiotensin receptor blocker (ARBs)?

- sartans

Answer 19

irbesartan

Question 20

What do ARBs do?

Answer 20

are angiotensin I receptor antagonists: inhibit angiotensin -induced vasoconstriction and aldosterone output; effect is reduced total peripheral resistance and increased Na+ and water excretion *no dry cough as seen in ACE inhibitors

Question 21

What are the indications for use of ARBs?

Answer 21

hypertension, heart failure, diabetic nephropathy, for patients intolerant to ACE inhibitors e.g. cough

Question 22

adverse effects of ARBs?

Answer 22

hypotension (less than ACE inhibitors), hyperkalaemia, avoid in pregnancy, beware of renal artery stenosis

Question 23

What do calcium channel blockers do?

Answer 23

block L-type (voltage operated) calcium channels, reduces Ca2+ entry into the vascular/cardiac cells *not skeletal muscle, therefore there is a reduction in intracellular calcium = vasodilation and reduced cardiac contractility and reduced atrioventricular conduction

Question 24

2 examples of calcium channel antagonists? Key difference between the two?

Answer 24

verapamil - reduces venous pressure (preload), has stronger effects on the heart
and amlodipine - reduces arteriolar pressure (afterload), stronger effects on HR (up), BP (down) and TPR (down)

Question 25

what are indications for calcium channel blockers/antagonists?

Answer 25

hypertensions, angina, tachydysrhythmias (TDRs)

Question 26

What are contraindications for calcium channel blockers?

Answer 26

heart failure or beta-blockers (with verapamil)

Question 27

Side effects of calcium channel blockers

Answer 27

- cardiac depression (both rate and force reduced), bradycardia (therefore contraindicated in heart failure) - flushing, oedema, dizziness, headache - constipation, nausea

Question 28

what do diuretics do?

Answer 28

- increase water and sodium excretion from the kidney - reduce circulating blood volume in hypertension; there is an initial drop in CO and; in longer term CO and TPR return to normal levels

Question 29

What do thiazides e.g. hydrochlorothiazide and indapamide act on?

Answer 29

distal tubule

Question 30

Example of a diuretic?

Answer 30

frusemide, more potent than thiazides, used in acute scenarios

Question 31

What do loop diuretics such as frusemide act on?

Answer 31

loop of Henle

Question 32

Uses of thiazides such as hydrochlorothiazide and frusemide?

Answer 32

- mild to moderate hypertension | - oedema due to: 1)congestive heart failure (+/- hypertension), 2) +/- pulmonary congestion and renal or liver disease

Question 33

Side effects of thiazides generally?

Answer 33

rash, hypokalaemia, hyperuricaemia, glucose intolerance, hyperchlesterolaemia

Question 34

Side effects of loop diuretics?

Answer 34

- hypovolaemia: dizziness, weakness, nausea, cramps, hypotension - hearing loss - increased magnesium, calcium excretion

Question 35

What is an important drug interaction with the use of diuretics?

Answer 35

Digoxin - toxicity is greatly increased | also consider K+ supplementation or combination with K+ sparing diuretics

Question 36

What do beta-adrenoceptor antagonists do - what are their effects?

Answer 36

decrease sympathetic input to the heart (therefore reduced CO and HR - and TPR to a lesser extent), inhibit renin release by decreasing Ang II levels, reduce sympathetic outflow from CNS if lipid soluble

Question 37

2 examples of beta-adrenoceptor antagonists and their selectivities?

Answer 37

Propranolol - non selective beta 1 and 2 antagonist | Atenolol - beta 1 selective antagonism

Question 38

Clinical uses for beta adrenoceptor antagonists?

Answer 38

angina, post myocardial infarct, hypertension, dysrhythmias, clinically stable heart failure

Question 39

Factors to consider when choosing a hypertensive

Answer 39

- patient's CV risk profile - presence of target organ damage, renal disease, diabetes - presence of coexisting conditions which may favour/limit use of particular classes (diabetes, respiratory) - individual patient variability to different classes - adverse effects - interactions with other co-prescribed drugs - cost, compliance

Question 40

Most effective combination for hypertension?

Answer 40

ACE inhibitor or ARB | + calcium channel blocker

Question 41

Other effective combination therapies?

Answer 41

- ACE inhibitor/ARB + thiazide diuretic esp. in heart failure or post stroke (low dose thiazide diuretic for people aged 65+) - ACE inhibitor/ARB + beta-blocker esp. post MI or heart failure - beta-blocker + dihydropyridine calcium channel blocker esp. coronary heart disease - thiazide diuretic + Ca2+ channel blocker - thiazide diuretic + beta-blocker *not recommended in people with glucose intolerance, metabolic syndrome or established diabetes

Question 42

In newly diagnosed hypertension, is it best to start with mono or combination therapy?

Answer 42

One drug to start, then 2 then 3. If after 3, target BP is still not reached, then refer to a specialist.

Question 43

Dangerous combinations to avoid

Answer 43

- ACE inhibitor/ARB antagonist + K+-sparing diuretic (risk of hyperkalaemia) - verapamil + beta-blocker (risk of heart block) - ACE inhibitor + Ang II receptor antagonist (increases risk of hypertensive symptoms, syncope and renal dysfunction)