antihypertensives

Question 1

drugs under angiotensin inhibitors?

Answer 1

ACE inhibitors (Lisinopril, Captopril, Enalapril)

ATI-Blockers/Angiotensin II Type 1 Blockers [ARBs] (Valsartan, Losartan)

Question 2

drugs under antihypertensives

Answer 2

angiotensin inhibitors, beta blockers, calcium channel blockers, diuretics

Question 3

mechanism of ACE inhibitors

Answer 3

1. inhibit ACE hence inhibiting conversion of angiotensin 1 to angiotensin 2

less Ang 2 –> less increase in peripheral resistance + Na+ and H2O retention

2. inhibit breakdown of bradykinins –> more production of NO and prostaglandins that stimulate vasodilation

Question 4

is ACE inhibitors contraindicated in pregnancy?

Answer 4

yes –> causes still birth

Question 5

use of ACE inhibitors

Answer 5

renal insufficiency, following a MI, cardiac failure, hypertension

Question 6

adverse effects of ACE inhibitors

Answer 6

severe hypotension, acute renal failure, hyperkalaemia, angioedema, dry cough

Question 7

mechanism of ARBs

Answer 7

inhibits Ang II from binding to its receptor

Question 8

are ARBs contraindicated in pregnancy

Answer 8

yes

Question 9

mechanism of beta blockers

Answer 9

inhibits binding of beta agonists to b-adrenoceptor –> less formation of cAMP

1. [b1-receptors] less PKA stimulated –> less calcium induced calcium release –> less Ca2+ influx –> reduced contractility
2. [b2-receptrs] less inactivation to inactivated MLCK –> more conversion to active myosin-LC –> more bronchoconstriction

Question 10

what are the beta blockers

Answer 10

Non selective: Propranolol, Pindolol, Carvedilol*
Cardioselective: Bisprolol, Metoprolol XL, Atenolol
Mixed: Nebivolol*

• for cardiac failure too

Question 11

clinical uses of beta blockers

Answer 11

hypertension, following a MI, cardiac failure, anxiety disorders, anti-arrhythmic

Question 12

adverse effects of beta blockers

Answer 12

AV nodal block, CNS effects like vivid dreams, hypotension, bradycardia, bronchoconstriction (in asthmatics), reduced exercise capacity

Question 13

beta blockers contraindicated in…?

Answer 13

diabetics

Question 14

thiazides mechanism

Answer 14

1. inhibit NaCl reabsorption at DCT
2. increase Ca2+ reabsorption
3. induce PG synthesis

Question 15

adverse effects of thiazides

Answer 15

Hypokalemic metabolic alkalosis, Hyponatraemia, Hypercalcaemia

Question 16

clinical uses of thiazides

Answer 16

Hypertension, Heart Failure, Nephrolithiasis due to idiopathic hypercalciuria, Nephrogenic Diabetes Insipidus, Early Stage Chronic Renal Failure, Osteopenia

Question 17

2nd line antihypertensives include

Answer 17

Hydralazine, Potassium Sparing Diuretics, Alpha-adrenoreceptor antagonists

Question 18

mechanism of Ca2+ channel blockers

Answer 18

1. Non-DHP → Less Ca2+ → reduces activity of SA and AV nodes → anti-arrhythmic
2. DHP → Less Ca2+ → reduces vascular smooth muscle tone (see anti-hypertensive lecture) → decreases BP → anti-hypertensive
3. Both DHP and non-DHP → reduction of myocardial contractility → reduces workload on the heart hence O2 requirement reduces + CO decreases hence decreases BP → anti-angina + anti-hypertensive

Question 19

clinical uses of Ca2+ channel blockers

Answer 19

Hypertension, stable angina, following MI and stroke

Question 20

adverse effects of Ca2+ channel blockers

Answer 20

Hypotension, MI, Heart failure

Question 21

Ca2+ channel blockers are contraindicated in

Answer 21

heart failure patients