Phamacological Management of Essential Hypertension - Revision Guide

Phamacological Management
of Essential Hypertension
Revision Tutorial
Next

Introduction
• This resource is a revision guide of the drugs used to treat
essential hypertension
• The first part of the resource summarises the key points of the
subject, including which drugs should be used and when, as
well as their cautions, contraindications and side effects
• The second part of the resource will provide questions for self
assessment
• This resource is a summary only, it does not contain all the
information available
• This resource aims to set out the important information in a
easy to understand and easy to learn format. The key points
that will be useful in a clinical situation will be highlighted
• Do not feel that you have to do everything in one session, if you
are tired then take a break and come back at another time
NextPrevious

Contents
• Introduction
• Treatment overview
• ACE inhibitors
• ARBs
• Calcium Channel Blockers
• Diuretics
• Beta blockers
• Alpha adrenoreceptor blockers
• Methyldopa
• Questions
Previous Next

Why Learn About Hypertension?
• Hypertension is common
– In the UK, about half of people over 65, and about 1
in 4 middle aged adults, have high blood pressure
• At least 1 in 20 adults have blood pressure of
160/100 mmHg or above
• High blood pressure is a risk factor for
developing a cardiovascular disease (heart
attack or stroke), and kidney damage
Previous Contents Next

Introduction to Hypertension
• The aim of treating hypertension is to reduce the patient’s blood
pressure in order to reduce their risk of cardiovascular disease.
• It is important to remember lifestyle changes that decrease
blood pressure and decrease cardiovascular risk in the absence
of a reduction in blood pressure. These should be discussed
with the patient before pharmacological treatment is started.
• Remember that you will be treating asymptomatic patients and
that treatment will be long term, it is therefore important to
consider a patient’s quality of life and how it will be affected by
the adverse effects of the treatment.

• Hypertension is defined as a blood pressure of over
140/90mmHg
• Blood pressure should be measured on three separate
occasions
• Patients should be offered drug treatment if:
– They have a blood pressure >160/100mmHg or
– They have an isolated systolic hypertension (>160mmHg) or
– They have a blood pressure >140/90mmHg and:
• 10 year CVD risk of at least 20% or
• Existing CVD or target organ damage
• The aim of treatment it to reduce blood pressure to
<140/90mmHg

• Treatment choice is based on British Hypertension
Society guidelines and NICE recommendations.
• First line treatment is to start the patient on one of:
Angiotensin Converting Enzyme (ACE) Inhibitor
Angiotensin II receptor Blocker (ARB)
Calcium Channel Blocker
Diuretic
• Drugs can be combined if treatment with one drug
does not achieve the target reduction (see next page)
• Additional drugs used for hypertension include beta
blockers, alpha adrenoreceptor blockers and centrally
acting drugs such as methyldopa

Guidelines For Treatment
Previous
Contents
Next Guidelines
from NICE and
BHS

ACE Inhibitors
• Inhibit conversion of angiotensin I to angiotensin II
(Affects RAAS  see next slide for diagram of RAAS)
• Examples of drugs in group:
– Captopril, Lisinopril, Ramipril, Perindopril
• Uses:
– Hypertension
– Prevention of cardiac remodelling following MI
– Treatment and prevention of diabetic nephropathy
– Treatment of heart failure

• Contraindicated in pregnancy, caution when prescribing to
female patients of childbearing age
• Avoid in patients with renovascular disease as can cause
renal impairment
• A small deterioration in renal function is often seen on starting
these drugs
• Can get first dose hypotension due to vasodilatation (more
common in patients with fixed cardiac output)
• If possible stop diuretics 2 days before starting ACE inhibitors
ACE Inhibitors – cautions and contraindications (CIs)

• Commonly causes a dry cough due to inhibition of bradykinin
metabolism
• Cause hyperkalaemia (caution when prescribing with
potassium sparing diuretics)
• ACE inhibitors are a good choice for treating hypertension in
diabetics as they treat and prevent diabetic nephropathy
• Hypersensitivity to ACE inhibitors occurs rarely and is
characterised by angio-oedema
• Do not give with NSAIDs
ACE Inhibitors – Side effects

Angiotensin Receptor Blockers
(ARBs)
• Antagonists of the angiotensin II receptor
• Angiotensin II receptors are classified into two subtypes – AT1
and AT2, AT1 receptors mediate all of the classical
pharmacological effects of angiotensin II. ARBs block AT1
• Example of drugs in group:
– Losartan, Candesartan, Eprosartan, Irbesartan, Olmesartan,
Telmisartan
• Uses:
– Hypertension
– Treatment and prevention of diabetic nephropathy
– Treatment of heart failure

• Similar to ACE inhibitors but do not cause dry cough,
therefore major use is in patients who are unable to
tolerate ACE inhibitors due to a dry cough
• Contraindicated in pregnancy
• Avoid in patients with renovascular disease
• A small deterioration in renal function is often seen on
starting these drugs
ARBs – cautions and CIs

• Can cause first dose hypotension
• If possible stop diuretics 2 days before starting ARB
• Good choice in patient with diabetes
• Can cause hyperkalaemia
• Hypersensitivity can occur, but is rare
• Do not give with NSAIDs
ARBs – Side effects

Calcium Channel Blockers
• Inhibit influx of calcium into cells
• Reduce myocardial contractility, depress formation
and propagation of electrical impulses within the heart,
decrease coronary and systemic vascular tone
• There are 3 groups of calcium channel blocker, they
have differential effects on the heart and peripheral
vasculature
– Dihydropyridines – peripheral vasculature
– Phenylalkylamines – heart
– Benzthiazepines – heart and peripheral vasculature

Dihydropyridines
• Affect peripheral vasculature more than heart
• Examples of drugs in this group:
– Amlodpipine, Felopdipine, Lacidipine, Nicardipine,
Nifedipine, Nimodipine
• Uses:
– Treatment of hypertension
– Prophylaxis of angina
– Prophylaxis of migraine (unlicensed)
– Prevention and treatment of neurological ischaemia
following SAH (subarachnoid haemorrhage)

• Avoid in pregnancy and breastfeeding
• Do not use for one month after an MI, do not use in
unstable angina
• Give as modified release formulation to avoid
exaggerated fall in BP
• Cause flushing, headache and peripheral oedema as
a result of vasodilatation
• Patients should avoid grapefruit juice as it increases
metabolism of the drugs
Dihydropyridines – cautions, CIs, side effects

Phenylalkylamines (verapamil)
• Affect heart more than peripheral vasculature
• Uses:
– Prevention of SVT (supraventricular tachycardia)
• Although verapamil can be used to treat hypertension
and angina, there are more appropriate choices for
these indications

• Take care in pregnancy and breastfeeding (no clear
evidence of harm)
• Avoid in patients with known left ventricular impairment or
heart failure as they are negatively inotropic
• Slows cardiac conduction – avoid in 2nd and 3rd degree
heart block
• Do not give with beta blockers
• Can cause hypotension
• Long term treatment can result in gynaecomastia
Phenylalkylamines – cautions, CIs, side effects

Benzthiazepines (diltiazem)
• Affect both the heart and peripheral
vasculature
• Uses:

• Avoid in pregnancy and breastfeeding
• Avoid in patients with heart failure as negatively inotropic
• Avoid in patients with 2nd or 3rd degree heart block
• Adverse effects - vasodilatation (flushing, headache,
peripheral oedema)
• Can cause hypotension
• Be careful when prescribing with beta blockers as there is a
risk of significant reduction in cardiac output
Benzthiazepines – cautions, CIs, side effects

Diuretics
• Thiazide diuretics, potassium sparing diuretics and
spironolactone are used to treat hypertension. They all
work in the distal convoluted tubule
• The antihypertensive effect of diuretics is not related
directly to their diuretic potency, but instead the BP
lowering action appears to depend upon more subtle
alterations to the contractile responses of vascular
smooth muscle
• Lower initial doses of diuretics should be used in the
elderly because they are particularly susceptible to the
side effects

Thiazide and Thiazide-like diuretics
• Thiazide = Bendroflumethiazide, Chlorothiazide,
Hydrochlorothiazide
• Thiazide like = Chlortalidone, Indapamide, Metolazone,
Xipamide
• Can cause hypokalaemia
• In hepatic failure hypokalaemia can precipitate
encephalopathy
• Can precipitate gout (thiazides interfere with the excretion of
uric acid)
• Can precipitate DM type II (diabetes mellitus) or worsen
glucose control in DM
• Do not use in pregnancy

• Can cause increased plasma lipid concentrations,
rashes and erectile impotence
• Ensure patient is not hypovolaemic before starting
diuretic therapy
• Ineffective in people with poor renal function because
they act from within the tubular lumen
• Low doses of thiazides are as effective as high
doses in the treatment of hypertension and cause
fewer side effects
Thiazide diuretics – cautions, CIs, side effects

Potassium sparing diuretics
• Examples of drugs in group;
– Amiloride, Triamterene
• Inhibit the Na+ channels in the apical membrane of
the late distal tubule and collecting duct
• Although they have diuretic action, their main use is
in combination with thiazide or loop diuretics in order
to conserve potassium

• Hypersensitivity reactions can occur but are
uncommon
• Triamterene can cause folate deficiency
• Do not use in patients with renal insufficiency
because they are at risk of hyperkalaemia
• Risk of hyperkalaemia when prescribed with –
ACE-I, ARBs, ciclosporin, NSAIDs, trimethroprim,
potassium supplements
K+ sparing diuretics – cautions, CIs, side effects

Spironolactone
• Aldosterone receptor antagonist
• Not used as first line therapy for hypertension
• Avoid in severe renal insufficiency
• Avoid in pregnancy and breast feeding
• Avoid in Addison’s disease
• Do not combine with other potassium sparing
diuretics
• Can cause painful gynaecomastia in men and
breast enlargement in women

Beta blockers
• Beta blockers are no longer used as a first line therapy
in the treatment of hypertension, see:
http://www.nice.org.uk/nicemedia/pdf/cg034quickrefguide.pdf
pages 8 and 9
– Propanolol, Atenolol, Bisoprolol, Metaprolol, Sotalol
• Beta1 specific blockers are relatively cardioselective
but still cause bronchoconstriction, all beta blockers
are contraindicated in asthma

• Do not give to patients with acute or unstable angina
• Can mask the physiological signs of hypoglycaemia
• Avoid in pregnancy unless absolutely necessary
• Do not stop treatment suddenly, rebound symptoms can be
severe
• Common adverse effects are cold limbs and peripheries and
a feeling of tiredness
• Can cause sleep disturbance and nightmares, erectile
impotence
• Sotalol occasionally causes life threatening ventricular
arrhythmias
Beta Blockers – cautions, CIs, side effects

Alpha1 adrenoreceptor blockers
• Act via selective blockade of peripheral alpha1
adrenoreceptors to produce vasodilator effects
• Not widely used first line treatments
– Prazosin, Doxazosin
• Associated with first dose hypotensive effect,
accompanied by reflex cardioacceleration and
palpitations, risk of vasovagal collapse

Treatment of hypertension
during pregnancy
• Methyldopa
• Beta blockers safe in 3rd trimester
• Modified release nifedipine also used

Methyldopa
• Centrally active antihypertensive drug, acts on central
alpha 2 adrenoreceptors to reduce sympathetic outflow
• Usually reserved for treatment of hypertension during
pregnancy
• Avoid in liver disease
• Do not give to patients with depression, porphyria or
phaeochromocytoma
• Do not stop suddenly as can cause rebound hypertension
• Adverse effects – sedation and tiredness, dry mouth,
diarrhoea

QUESTIONS

Questions
• There are 20 questions in this session
• They are designed to help you test your knowledge of
material that has been covered
• Click on an answer to see if it is correct
• Keep a record of your score
• If you are unsure why something is correct or incorrect
go back to the relevant section, you can navigate back
to the question you were on by going to
Contents  Questions  choose the question number
NextPrevious Contents

Questions
Q1 Q6
Q2 Q7
Q3 Q8
Q4 Q9
Q5 Q10
Q11 Q16
Q12 Q17
Q13 Q18
Q14 Q19
Q15 Q20
Start Questions

Question 1
Which of these drugs is a beta blocker?
Ramipril
Nifedipine
Atenolol

RAMIPRIL
INCORRECT
Ramipril is an ACE inhibitor
Back to Question 1
Beta Blockers

NIFEDIPINE
INCORRECT
Nifedipine is a calcium channel blocker
Beta Blockers
Back to Question 1

ATENOLOL
CORRECT
This is a beta blocker
Next Question

Question 2
Which of these drugs does not cause
hypokalaemia?
Lisonipril
Indapamide
Bisoprolol

LISONIPRIL
INCORRECT
Lisonipril is an ACE-inhibitor, it can cause
hypokalaemia
Back to Question 2
ACE-Inhibitors

INDAPAMIDE
INCORRECT
Indapamide is a thiazide-like diuretic, it can
cause hypokalaemia
Diuretics
Back to Question 2

BISOPROLOL
CORRECT
Bisoprolol is a beta blocker, it does not
cause hypokalaemia
Next Question

Question 3
Which of these is the best choice for
treating hypertension in diabetic patients?
Perindopril
Metolazone
Atenolol

PERINDOPRIL
CORRECT
This is an ACE-inhibitor, it can be used to
treat and prevent diabetic nephropathy
and is a good choice for diabetic patients
Next Question

METALAZONE
INCORRECT
Metalazone is a thiazide-like diuretic, these
drugs can precipitate type II diabetes
mellitus or worsen glucose control in
diabetes
Back to Question 3
Diuretics

ATENOLOL
INCORRECT
Atenolol is a beta blocker, it can mask the
physiological responses to hypoglycaemia, they
are not contraindicated in diabetes, but they
should not be given to patients who have
frequent episodes of hypoglycaemia
Beta Blockers
Back to Question 3

Question 4
Which of these groups of calcium channel
blockers does nifedipine belong to?
Phenylalkylamines
Dihydropyridines
Benzthiazepines

PHENYLALKYLAMINES
INCORRECT
Verapamil is an example of a drug in this
group
Back to Question 4

DIHYDROPYRIDINES
CORRECT
Drugs in this group tend to have the suffix ‘-ine’
Next Question

BENZATHIAZEPINES
INCORRECT
Diltiazem is an example of a drug in this
group
Back to Question 4

Question 5
Which of these is a calcium channel
blocker?
Diltiazem
Digoxin
Doxazosin

DILTIAZEM
CORRECT
Diltiazem is a calcium channel blocker
Next Question

DIGOXIN
INCORRECT
Digoxin is a cardiac glycoside, it is used as
an antiarrhythmic drug and in the
treatment of heart failure
Back to Question 5

DOXAZOSIN
INCORRECT
Doxazosin is an alpha1 receptor blocker
Back to Question 5

Question 6
Which of these is safe to use during
pregnancy?
Captopril
Methyldopa
Bendroflumethiazide

CAPTOPRIL
INCORRECT
Captopril is an ACE inhibitor, ACE inhibitors
can cause birth defects
Back to Question 6
ACE-Inhibitors

METHYLDOPA
CORRECT
Methyldopa is the first choice drug for
hypertension during pregnancy
Next Question

BENDROFLUMETHIAZIDE
INCORRECT
Bendroflumethiazide is a thiazide diuretic, it
can cause neonatal thrombocytopenia if
given during pregnancy
Diuretics
Back to Question 6

Question 7
Which of these is used to treat hypertension?
Amiodarone
Adenosine
Amlodipine

AMIODARONE
INCORRECT
Amiodarone is an antiarrhythmic drug, it is
not used to treat hypertension
Back to Question 7
Contents

ADENOSINE
INCORRECT
Adenosine is an antiarrhthymic drug which is an
antagonist at the purine A2 receptors, it is not
used to treat hypertension
Contents
Back to Question 7

AMLODIPINE
CORRECT
Amlodipine is a calcium channel blocker, it is
used as a first line treatment of
hypertension
Next Question

Question 8
ARBs do not cause a dry cough
TRUE
FALSE

TRUE
CORRECT
ARBs do not cause a dry cough, ACE inhibitors
cause a dry cough because they inhibit
bradykinin metabolism, ARBs do not inhibit
bradykinin metabolism, they are used for
patients who are intolerant to ACE-inhibitors
because of the dry cough
Next Question

FALSE
INCORRECT
ARBs do not cause a dry cough, ACE inhibitors
cause a dry cough because they inhibit
bradykinin metabolism, ARBs do not inhibit
bradykinin metabolism, they are used for
patients who are intolerant to ACE-inhibitors
because of the dry cough
ARBs
Next Question

Question 9
ARBs block AT2 receptors
TRUE
FALSE

TRUE
INCORRECT
ARBs block AT1 receptors. AT1 receptors
mediate all the classical pharmacological
effects of angiotensin II, the functional role
of AT2 receptors in unclear
Next Question
ARBs

FALSE
CORRECT
ARBs block AT1 receptors. AT1 receptors
mediate all the classical pharmacological
effects of angiotensin II, the functional role
of AT2 receptors in unclear
Next Question

Question 10
The correct definition of hypertension
is:
A blood pressure > 135/85mmHg

135/85mmHg
INCORRECT
If you are unsure why this is incorrect then see
the introductory slide on hypertension or follow
this link:
http://www.nice.org.uk/nicemedia/pdf/cg034quickr
efguide.pdf
Back to Question 10
Introduction

140/90mmHg
CORRECT
Hypertension is defined by WHO as a blood
pressure >140/90mmHg
Next Question

160/100mmHg
INCORRECT
This is the blood pressure at which drug therapy
should be considered with a 10 year
cardiovascular risk of less than 20% and no
cardiovascular or target organ damage
Introduction
Back to Question 10

Question 11
Which of these is not a
contraindication for ACE-inhibitors?
Renovascular disease
Pregnancy
Diabetes Mellitus

RENOVASCULAR DISEASE
INCORRECT
ACE-inhibitors can cause severe renal
impairment in patients with renovascular
disease
Back to Question 11
ACE-Inhibitors

PREGNANCY
INCORRECT
ACE-inhibitors can cause birth defects and
are contraindicated in pregnancy
ACE-Inhibitors
Back to Question 11

DIABETES MELLITUS
CORRECT
ACE-inhibitors can be used to treat and
prevent diabetic nephropathy in Type 1
Diabetes Mellitus
Next Question

Question 12
Thiazide diuretics are the first choice
for patients with renal impairment
TRUE
FALSE

TRUE
INCORRECT
Thiazides are ineffective in patients with
poor renal function as they work from
within the tubular lumen
Next Question
Diuretics

FALSE
CORRECT
Thiazides are ineffective in patients with
poor renal function as they work from
within the tubular lumen
Next Question

Question 13
Which of these is an alpha1
adrenoreceptor blocker?
Doxazosin
Metaprolol
Nimodipine

DOXAZOSIN
CORRECT
Doxazosin is an alpha1 adrenoreceptor
blocker
Next Question

METAPROLOL
INCORRECT
Metaprolol is a beta blocker
Back to Question 13
Alpha Receptor Blockers

NIMODIPINE
INCORRECT
Nimodipine is a calcium channel blocker
Alpha Receptor Blockers
Back to Question 13

Question 14
Cardioselective beta blockers cause
bronchoconstriction and should not be
used in patients with asthma
TRUE
FALSE

TRUE
CORRECT
Cardioselective beta blockers are only
relatively selective (they still have some
effect on other receptors) and still cause
bronchoconstriction
Next Question

FALSE
INCORRECT
Cardioselective beta blockers are only
relatively selective (they still have some
effect on other receptors) and still cause
bronchoconstriction
Next Question
Beta Blockers

Question 15
Which of these is not a first line
treatment for hypertension?
Propanolol
Ramipril
Felodipine

PROPANOLOL
CORRECT
This is a beta blocker. Beta blockers are no
longer used as a first line treatment for
hypertension, for more information see:
http://www.nice.org.uk/nicemedia/pdf/cg034
quickrefguide.pdf
Next Question

RAMIPRIL
INCORRECT
Ramipril is an ACE inhibitor, it is often used
as a first line treatment for hypertension
Back to Question 15
ACE-Inhibitors

FELODIPINE
INCORRECT
Felodipine is a calcium channel blocker, it is
often used as a first line treatment for
hypertension
Back to Question 15

Question 16
Which of these is an ACE-inhibitor?
Doxazosin
Captopril
Amiloride

DOXAZOSIN
INCORRECT
Doxazosin is an alpha adrenoreceptor
blocker
Back to Question 16
ACE-Inhibitors

CAPTOPRIL
CORRECT
This is an ACE-inhibitor, ACE-inhibitors tend
to have the suffix ‘-pril’
Next Question

AMILORIDE
INCORRECT
Amiloride is a potassium sparing diuretic
ACE-Inhibitors
Back to Question 16

Question 17
Diltiazem blocks calcium channels in
both cardiac and skeletal muscle
TRUE
FALSE

TRUE
INCORRECT
Diltiazem blocks calcium channels in cardiac
and smooth muscle but not in skeletal
muscle
Next Question

FALSE
CORRECT
Diltiazem blocks calcium channels in cardiac
and smooth muscle but not in skeletal
muscle
Next Question

Question 18
Thiazide diuretics cause:
Hypokalaemia
Hypocalcaemia
Hypouricaemia

HYPOKALAEMIA
CORRECT
Thaizide diuretics cause an increased
urinary loss of potassium which can lead
to hypokalaemia
Next Question

HYPOCALCAEMIA
INCORRECT
Hypercalcaemia is a rare adverse effect of
thiazide diuretics resulting from reduced
renal excretion of calcium
Back to Question 18
Diuretics

HYPOURICAEMIA
INCORRECT
Thiazide diuretics interfere with the
excretion of uric acid and can cause
hyperuricaemia
Diuretics
Back to Question 18

Question 19
Which of these drugs should not
be taken with grapefruit juice?
Verapamil
Spironolactone
Nifedipine

VERAPAMIL
INCORRECT
This is not one of verpamil’s drug
interactions
Back to Question 19

SPIRONOLACTONE
INCORRECT
This is not one of Spironolactone’s drug
interactions
Diuretics
Back to Question 19

NIFEDIPINE
CORRECT
Grapefruit juice affects the metabolism of
dihydropyridines (except amlodipine) and
therefore increases the risk of adverse
effects
Next Question

Question 20
Increasing the dose of a thiazide
diuretic does not cause a greater
decrease in blood pressure
TRUE
FALSE

TRUE
CORRECT
Low doses are as effective as higher doses,
higher doses have a higher incidence of
adverse effects
Results

FALSE
INCORRECT
Low doses are as effective as higher doses,
higher doses have a higher incidence of
adverse effects
Results
Diuretics

Results
• Score 0-10 You need to do more revision
• Go back through this guide or read crash course
pharmacology
• Score 10-15 Good score, but you could do
better, look up the things you struggled
with and try again
• Score 15-20 Excellent, well done, now make
sure you don’t forget everything
References

References
• Lecture Notes on Clinical Pharmacology, 6th
Edition. Reid, Rubin and Whiting. Blackwell
Science
• Companion to Pharmacology, 2nd
edition. Dale
and Dickenson. Churchill Livingstone
• Oxford Handbook of Practical Drug Therapy.
Richards and Aronson. Oxford University Press
• British National Formulary, edition 53 March
2007
• http://www.nice.org.uk/nicemedia/pdf/cg034quick
refguide.pdf
End

Phamacological Management of Essential Hypertension - Revision Guide

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