Treatment of Hypertension

Question 1

What are the lifestyle changes to make when treating hypertension?

Answer 1

Reduce overall cardiovascular risk

Reduce alcohol consumption

Weight reduction

Reduce excess caffeine

Reduce salt + fat intake

Increase fruit + oily fish in diet

Increasing exercise

Smoking cessation

Question 2

Identify when and which patients should receive pharmacological therapy for hypertension

Answer 2

Stages of hypertension:

1. Stage 1: >140/>90mmHg
2. Stage 2: >160/>100mmHg
3. Severe: >180/>110mmHg

Treat stage 1 hypertension with one or more of the following conditions:

• end organ damage
• diabetes
• CV disease
• high CV risk

Must treat all patients with stage 2

Question 3

Describe the mode of action of ACE inhibitors

Answer 3

e.g. captopril, enalapril, perindopril, ramipril

ACE inhibitors inhibit the ACE enzyme which inhibit the formation of angiotensin II. This leads to:

• Vasodilatation
• Reduced aldosterone production leads to reductions in salt + water retention
• Increased bradykinin - causes dry cough (side effect)

Question 4

Identify important adverse effects to ACE inhibitors

Answer 4

Cough (10% of patients)

Increase K + interact with salt (KCl)

Angioedema - swelling of the eyes + lips

ACEI should be avoided in renovascular disease (kidneys)

• with renin-dependent hypertension, ACEIs lead to renal underperfusion + severe hypotension
• can worsen renal function - if so, discontinue
• monitor creatinine before + during use
• can prevent nephropathy in diabetes mellitus

Question 5

Describe the mode of action of angiotensin AT1 receptor antagonists

Answer 5

e.g. candesartan, losartan, valsartan

Block the action of AII at the AT₁ (type 1 angiotensin II) receptor

They have similar consequences as ACEIs but do not give rise to a cough

• due to the fact they do not inhibit ace causing an increase in bradykinin

Question 6

Describe the mode of action of Renin inhibitors

Answer 6

e.g Aliskiren (new)

They inhibit renin enzyme

Question 7

Describe the mode of action of calcium channel blockers

Distinguish between rate-limiting agents and the actions of dihydropyridines

Answer 7

e.g. diltiazem, verapamil & dihydropyridines (amlodipine, felodipine, nifedipine)

Inhibit Ca²⁺ channels on vascular smooth muscle

• leads to vasodilatation + BP reduction

2 classes of CCBs:

• rate-limiting (e.g. verapamil) - selective on cardiac tissue
• dihydropyrimidines (e.g. amlodipine) - selective on vascular smooth muscle

Question 8

Describe the mode of action of thiazide-like diuretics

State the side effects of this type of diuretic

Answer 8

e.g. chlortalidone + indapamide

3^rd line antihypertensives

Inhibit Na⁺/Cl^{<strong>-</strong>} in distal convoluted tubule

• Reduction in circulating volume
• Causes vasodilatation

Ineffective in renal impairment

Measure renal function

• must measure renal function (creatinine) before + during use

Side effects:

• hypokalaemia
• postural hypotension
• impaired glucose control - diabetes
• do not use in gout

Question 9

Describe the mode of action of alpha blockers as antihypertensives

Answer 9

e.g. doxazosin, prazosin

Competitive a₁-adrenoceptor receptor antagonist

• Last choice of antihypertensives*
• Widespread side effects, poorly tolerated*

Question 10

Describe the mode of action of beta blockers as antihypertensives

Answer 10

e.g. atenolol, propranolol

Reduction in sympathetic drive to the heart - reduces cardiac output

Reduces sympathetically evoked renin release

Beta-blockers (even Beta₁ selective agents) block bronchial beta_{<strong>2</strong>} adrenoceptors + contraindicated in asthma + caution in COPD

Question 11

State the common adverse effects of ACEIs

Answer 11

Cough

Severe first dose hypotension

Renal damage

Question 12

State the common adverse effects of CCBs

Answer 12

Peripheral oedema

Headaches

Postural hypotension

Constipation

Question 13

State the common adverse effects of Thiazides

Answer 13

Urination

Diabetogenic

Alter lipid profile

Hypokalaemia

Impotence

Postural hypotension

Question 14

State the common adverse effects of beta-blockers

Answer 14

Bronchospasm

Reduce hypoglycaemic awareness

Question 15

State the common adverse effects of Alpha-blockers

Answer 15

Widespread

Postural hypotension

Question 16

Which antihypertensive drug should be used for ischaemic heart disease?

Answer 16

Beta-blocker

Question 17

Which antihypertensive drug should be avoided in asthma?

Answer 17

Beta-blocker

Question 18

Which antihypertensive drug should be used in diabetic nephropathy?

Answer 18

ACE inhibitors

Question 19

Which antihypertensive drug should be avoided in renovascular disease?

Answer 19

ACE inhibitors

Question 20

Which antihypertensive drug should be used in congestive heart failure?

Answer 20

ACE inhibitors

Question 21

Which antihypertensive drug should be avoided in gout?

Answer 21

Thiazides

Question 22

Identify compelling reasons to use or avoid certain antihypertensives

Question 23

Critically apply the A/C guidelines on the management of hypertension

Answer 23

Question 24

What is the ASCOT 2005 study?

What did it show?

Answer 24

This study compared the blood pressure lowering effects of Atenolol with Bendroflumethiazide to those of Amlodipine with Perindopril.

Equal BP control

Amlodipine reduced cardiovascular events more + induced less diabetes

Amlodipine-based therapy is superior in patients @ moderate risk of CV disease

Question 25

What was the ALLHAT study?

What was the outcome?

Answer 25

Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT)

Thiazide-type diuretics are superior in preventing 1/more major forms of CVD

Thiazides are viewed as 1^st line drugs (even with diabetic pts)

Question 26

What did the heart protection study show?

Answer 26

Statin, simvastatin reduced cardiovascular events in high risk pts - even with normal cholesterol

Statins should be considered for all high risk pts - irrespective of cholesterol level