Antihypertensives

Question 1

Give an example of a B1 selective, non-selective and a1 selective Beta-blocker?

Answer 1

B1 selective: Atenolol, Metoprolol
Non-selective: Propanolol
a1-selective: Carvedilol

Question 2

Describe the MAO of B-blockers?

Answer 2

• Negative chronotropic (HR) and ionotropic (contractility) effects)
• Decreased HR -> decreased cardiac O2 requirement -> adequate myocardial oxygenation
• RAAS: Blocks renin release -> decrease aldosterone -> decrease Na and Cl resorption -> decrease water resorption -> decrease blood volume -> decrease BP
• Peripheral vasodilation

Question 3

What are the indications for B-blocker use?

Answer 3

Angina, MI, SVT, HTN, HF, glaucoma (Timolol), variceal bleeding (Propanolol)

Question 4

List B-blocker side effects.

Answer 4

Side effects: erectile dysfunction, cardiovascular (bradycardia, AV block, HF), CNS (seizures, sedation, sleep alterations), dyslipidaemia (metoprolol), asthma/COPD exacerbations

Caution: cocaine users (risk unopposed a-adrenergic receptor agonist activity), concern masking hypoglycaemia in diabetics (benefits outweigh risks)

Question 5

Give examples of CCBs?

Answer 5

Amlodipine, Nicardipine, Nifedipine

Question 6

Describe the MAO of CCBs?

Answer 6

• Inhibits Ca influx into cardiac and smooth muscle -> negative ionotropic effect (contractility)
• Slows down electrical conduction -> negative chronotropic effect (HR)
• Relaxation of arterial smooth muscle (vasodilation) -> decrease TPR -> decrease BP

Note: decreased TPR evokes baroreceptor-mediated sympathetic discharge -> increased HR

Question 7

Name CCB indications?

Answer 7

Angina, HTN, AF, SAH (prevent cerebral vasospasm), Raynoud phenomenon

Question 8

Give examples of ACEI?

Answer 8

Enalopril, Rimipril, Captopril

Question 9

Describe the MAO of ACEI?

Answer 9

• Inhibit ACE -> decrease angiotensin II –
• Prevent efferent arteriole constriction -> decrease GFR
• Decrease aldosterone -> diuresis -> decrease BP
• Decrease tubular resorption of Na and Cl
• Also prevents inactivation of bradykinin (potent vasodilator) -> decrease TPR

Question 10

List indications for ACEI use?

Answer 10

HTN, HF, proteinuria, diabetic nephropathy

Question 11

Name some ACEI side effects?

Answer 11

SE: cough, angioedema (increased bradykinin), teratogen, increased creatinine (decreased GFR), hyperkalaemia, hypotension

Note: used w caution in bilateral renal a stenosis (further increases GFR -> renal failure)

Question 12

Give examples of angiotensin II receptor blockers (ARBs)?

Answer 12

Losartan, candesartan, valsartan

Question 13

Describe the MAO of ARBs?

Answer 13

Selectively block binding of angiotensin II to AT1 receptor
• Prevent efferent arteriole constriction -> decrease GFR
• Decrease aldosterone -> diuresis -> decrease BP
• Decrease tubular resorption of Na and Cl

Question 14

List indications for ARB use?

Answer 14

HTN, HF, proteinuria, diabetic nephropathy (w ACE-I intolerance)

Question 15

What are some SE of ARB use?

Answer 15

Hyperkalaemia, decreased GFR, hypotension, teratogen

Question 16

Give an example of a loop diuretic?

Answer 16

Furosemide, Bumetanide, Torsemide

Question 17

What is the MAO of Furosemide?

Answer 17

MA: sulfonamide loop diuretics
• Inhibit cotransport system (Na+/K+/Cl-) of thick ascending limb of loop of Henle
• Abolish hypertonicity of medulla -> prevents concentration of urine
• Stimulate PGE release -> vasodilation of afferent arteriole

Note: increased Ca+2 excretion
Inhibited by NSAIDs

Question 18

List loop diuretic indications?

Answer 18

Oedematous states (HF, cirrhosis, nephrotic syndrome, pulmonary oedema), HTN, hypercalcaemia

Question 19

List some SE of loop diuretics?

Answer 19

SE (OH DANG acronym): ototoxicity, hypokalaemia, dehydration allergy, metabolic alkalosis, nephritis (interstitial), gout

Question 20

Give some examples of K-sparring diuretics?

Answer 20

Spironolactone, Triamterene, Amiloride

Question 21

What is the MOA of K-sparring diuretics?

Answer 21

MA: aldosterone antagonist -> decreased Na+ and Cl- resorption, water retention and increased K+ excretion -> decreased blood volume

Question 22

List indications for K-sparring diuretic use?

Answer 22

Hyperaldosteronism, K+ depletion, HF, hepatic ascites (Spironolactone), nephrogenic DI (Amiloride)

Question 23

List some SE of K-sparring diuretics?

Answer 23

Hyperkalaemia (arrhythmia), endocrine w Spironolactone (gynaecomastia, antiandrogen effects)

Question 24

Give examples of thiazide diuretics?

Answer 24

Hydrochlorothiazide, chlorthalidone, metolazone

Question 25

Explain the MAO of thiazide diuretics?

Answer 25

MA: inhibit NaCl resorption at early distal convoluted tubule
-> decreased water resorption
-> decreased blood volume
-> decreased BP
• Mild vasodilation
• Increase Ca+2 excretion
• More modest effects than loop diuretics

Note: additive effects with ACE-I

Question 26

List some indications for thiazide diuretic use?

Answer 26

HTN, HF, idiopathic hypercalciuria, nephrogenic DI, osteoporosis

Question 27

What are the SE of thiazide diuretic use?

Answer 27

Hypokalaemia, metabolic alkalosis, hyponatraemia, hyperglycaemia, hyperlipidaemia, hyperuricaemia, hypercalcaemia, sulfa allergy

Question 28

Describe the MAO of alpha-adrenergic receptor antagonists?

Answer 28

MA: arterial and venous vasodilation -> decreased TPR -> decreased BP

Question 29

What are some SE of alpha-adrenergic receptor antagonists?

Answer 29

SE: postural hypotension, weakness, drowsiness

Question 30

What is the MAO of centrally acting antihypertensives?

Answer 30

MA: act in the brainstem to decrease sympathetic outflow from brain to decrease vascular tone

Question 31

List some SE of centrally acting antihypertensives?

Answer 31

SE: sedation, sleep disturbance, dreams, depression

Question 32

What is the hypertension treatment algorithm?

Answer 32

1. ACE/ARB
2. ACE/ARB + CCB
3. ACE/ARB + CCB + Thiazides