Drug Therapy For Hypertension

Question 1

ACE Inhibitors

Answer 1

Prototype- Captopril
Expected pharmacological action- produce their anti hypertensive effect by blocking production of angiotensin ll. When angiotensin is blocked, arteriolar vasodilation occurs.
Adverse reactions- occur after first dose, servere hypotension.
Side effects- rash and metallic taste in mouth.
Administration- oral use only

Question 2

ARBs

Answer 2

Prototype- losartan
Expected pharmacological action- produce antihypertensive effect by blocking angiotensin ll receptors. When angiotensin ll receptors are blocked, angiotensin ll is unable to bind to those receptor sites, thus resulting in arteriolar vasodilation, urinary excretion or sodium and water, and retention or potassium.
Adverse reactions- angioedema
Administration- oral only

Question 3

Alpha1 Blockers

Answer 3

Prototype- doxazosin
Expected pharmacological action- block alpha1 receptors, which prevents them from being stimulated
Adverse reactions- orthostatic hypotension, reflex tachycardia
Administration- oral only

Question 4

Beta blockers

Answer 4

Prototype- atenolol
Expected pharmacological action- exert their anti hypertensive effects in an indirect manner. In the heart, they block beta1 receptors which causes a decrease in heart rate and contractility. In the kidney, they block renal beta1 receptors, causing a decrease in the release of renin. Beta1 blockers also decrease peripheral resistance of blood vessels by an unknown mechanism.
Adverse reactions- bradycardia
Administration- orally, IV

Question 5

Centrally acting alpha2 agonists

Answer 5

Prototype- clonidine
Expected pharmacological action- exhibit their antihypertensive effects by selectively activating alpha2 receptors in the brain stem areas of the CNS. This results in reduction of sympathetic stimulation of the heart and associated blood vessels, reducing blood pressure.
Adverse reactions- drowsiness and dizziness
Administration- orally, transdermal patch

Question 6

Alpha/Beta blockers

Answer 6

Prototype- carvediol
Expected pharmacological action- act by blocking both alpha and beta receptors in the heart, arteriosclerosis and kidney.
Adverse reactions- dizziness, hypotension, bradycardia.
Administration- orally