Blood pressure regulators

Question 1

Hypotensive activity of drugs

Answer 1

decrease preload -> venodilation and reduced circulating blood flow volume
decrease afterload-> arteriodilation
decrease CO -> Negative inotropy, negative chronotropy

Question 2

ACE-I

Answer 2

Inhibition of angiotensin converting enzyme
Vasodilation – hypotensive effect
↓ Heart preload and afterload, ↓ Cardiovascular remodelation, ↓Aldosterone secretion

Kaptopril short-acting
Enalapril/Enalaprilate(prodrug)
Perindopril

 Arterial hypertension
 Chronic heart failure
 Coronary heart disease/ myocardial infarction
 Diabetic nephropathy

SE: dry cough
(↑bradykinin),
hyperkalemia
(↓aldosterone)

Question 3

Angiotensine receptor AT1 blockers

ARB

Answer 3

Blocks angiotensine II binding to
AT1 receptors
Venous and arterial vasodilation
(both ACE-I and ARB)

Does not affect bradykinin metabolism

Valsartan
Candesartan
Losartan

 Arterial hypertension
 Chronic heart failure

SE: Hyperkalemia

Question 4

Calcium channel blockers

Answer 4

Arterial vasodilators
(↓ heart afterload)

inhibits Ca2 + entry into the heart and b /v muscle cells
In the smooth muscle Ca2+ and calmoduline complex does not form→ myosin light chain kinase is not activated →smooth muscle relaxes

Nifedipine
Amlodipine d.a. 24 h
Nicardipine

 Arterial hypertension
 Prophylaxis (stable exertion) of angina pectoris
 Coronary heart disease (vasospastic form)

SE: constipation, Peripheral edema (ankles)

Question 5

BAB

Answer 5

Decrease Heart rate and myocardium contractility
reduction, that ↓CO

2. Antagonistic effects on
renal juxtaglomerular
β1-adrenoceptors which ↓ renine
secretion, but clinically significant
vasodilation it does not cause.
1., 2. generation BAB can cause reflector
vasoconstriction

3. Peripheral arterial vasodilation
Is not direct BAB activity,
But is an additional activity of several BAB
with hybrid effect, i.e. 3rd generation
BAB (e.g. nebivolol) 

Metoprolol, propanolol, carvedilol, bisoprolol, nebivilol

Question 6

SIRA

Answer 6

Centrally acting- don’t cause reflector tachycardia
Moxonidine
* imidazoline receptors are mainly concentrated in the ventrolateral part of the medulla oblongata
SIRA decreases SNS activity which decreases BP

 AH + metabolic syndrome
(↑ tissue sensitivity to insulin)

Question 7

Metildopa

Answer 7

Centrally acting antihypertensive agent—>alpha 2 autoreceptor agonist

Crosses BBB, decarboxilates to methyldopamine→
the active metabolite methylnorepinephrine →inhibits dopa-decarboxilaze.
As a false mediator, presynaptically accumulates in vesicles and stimulates presynaptic alpha 2 autoreceptors

 Gestational hypertension

Question 8

Emergency antihypertensives

Answer 8

Sodium nitroprusside and Labetolol

Question 9

NO modulators

Answer 9

Sodium nitroprusside i/v
Short-acting
Direct action vasodilator, NO donor→ cGMP↑
↓ heart preload and afterload

 Antihypertensive help in emergencies

Question 10

Labetalol

Answer 10

Combined alpha and beta adrenoreceptor block

 Antihypertensive help in emergencies and urgent situations