Treatment of Hypertension Flashcards
What is the definition of stage 1 hypertension?
- Clinic blood pressure is 140/90 mmHg or higher
- ABPM daytime average 135/85 mmHg or higher.
What is stage 2 hypertension?
•Clinic blood pressure is 160/100 mmHg or higher
ABPM daytime average 150/95 mmHg or higher
What is severe hypertension?
•Clinic systolic blood pressure is 180 mmHg or higher or diastolic blood pressure is 110 mmHg or higher.
How does blood pressure change in the night time?
Dips - Loss of nocturnal dip in blood pressure has massive health consequences
How do you assess risk of hypertensive patients? (6)
–Previous MI, stroke, IHD
–Smoking
–Diabetes mellitus
–Hypercholesterolaemia
–Family history
–Physical Examination
How can you assess end organ damage of left ventricular hypertrophy?
ECG and Echocardiogram
How do you measure kidney function for end organ damage?
Renal ultrasound
eGFR (estimated glomerular filtration rate)
Proteinuria
Presence of abnormal quantities of protein in urine, may indicate damage to kidneys.
What are the common treatable causes of hypertension?
Renal artery stenosis / fibromuscular dysplasia
Endocrine diseases - Chushings disease, Conn’s disease
Sleep apnoea
(Cushing’s syndrome is caused by either excessive cortisol-like medication such as prednisone or a tumour that either produces or results in the production of excessive cortisol by the adrenal glands. Cases due to a pituitary adenoma are known as Cushing’s disease)
(Conn’s disease excess production of hormone aldosterone by adrenal glands resulting in low renin levels. Often produces few symptoms. Most people have high blood pressure which may cause poor vision or headaches)
What is effective treatment for reducing left ventricular mass?
ACE or ARB
How does hypertension change with age?
Increases
What is the target blood pressure according to BHS?
< 135/80-85 mmHg
When does treatment for hypertension usually start?
CVD risk of 20% / 10 years
(no end organ damage, stage 1 hypertension)
What are the reasons for treating hypertension?
–reduce cerebrovascular disease by 40-50%
–reduce MI by 16-30%
What is the format of treatment of hypertensives?
Stepped approach
- introduce one drug, then a second then a third
- uses a dose less than maximum dose
- minimises max dose use so less side effects
Low doses of several drugs
- minimises adverse events and maximises patient compliance
What are the differences in renin between the young and the old?
Young - high renin
Old - low renin
What type of drugs do you give to young vs Elderly (over 55)
Young:
- ACE inhibitor / ARB - these are teratogenic
Elderly:
- Calcium channel blocker - Thiazide type diuretic
When should we start giving treatment to patients over 80 years old?
ABPM >135/85 with one or more of the following:
- target organ damage
- established cardiovascular disease
- renal disease
- diabetes
- 10-year cardiovascular risk equivalent to 20% or greater.
When do we give treatment to people who have stage 2 hypertension?
Offer antihypertensive drug treatment to people of any age with stage 2 hypertension
What should you do for patients under 40 years with stage 1 hypertension or greater?
Always refer if younger than 40 – usually due to lifestyle like alcohol and cocaine
How does treatment for patients who are 55-80 years differ for patients who are over 80 years old?
Same treatment taking into account co-morbidities - blood pressure target is different- (•<145/85)
Drugs reduce blood pressure – end up falling over – can’t achieve same amount of control
- Falling over affects confidence of old people
What would you suggest for people identified as having ‘white coat effect’?
ABPM / HBPM - measures blood pressure and monitors effect of antihypertensive drugs or lifestyle changes
What is step 1 treatment for a patient under 55 years?
ACEI or ARB (angiotensin receptor blocker)
Not if afro carribean or woman of child bearing age
Why can’t you give an afrocarribean or woman of child bearing age ACEI or ARB?
Afro- Caribbean
- low renin hypertension – ace inhibitor and ARB’s are less effective and more expensive.
- more susceptible to ankle oedema
- Can be life threatening
Women of child baring age
- teratogenic
What is step 2 treatment?
Add thiazide-type diuretic such as clortalidone or indapamide to CCB or ACEI/ARB
What is step 3 treatment?
Add CCB, ACEI, Diuretic together
What is step 4 treatment?
Further diuretic therapy - low dose spironolactone (spyro - no - lactonoe)
Can only use in people with low potassium-
•caution in people with reduced estimated GFR, increased risk of hyperkalaemia.
–Consider higher-dose thiazide-like diuretic treatment if the blood potassium level is higher than 4.5 mmol/l.
What is the effect of a thiazide like diuretic?
Acts on nephron at proximal part of distal tubule. Transfer of sodium and water across membranes is interrupted - increasing sodium excretion and urine volume - reduction in blood volume.
ALSO
In long-term, major haemodynamic effect is reduction in peripheral resistance due to subtle alterations in contractile responses of vascular smooth muscle.
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If over 55 years?
A calcium channel blocker instead of ACEI/ARB
Give examples of ACEI
Rampril and perindopril
- Competitively inhibit actions of angiotensin converting enzyme (ACE)
What is the function of angiotensin 2?
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What is a common side effect of an ACE I?
Cough
What is the end organ damage associated with the heart caused by angiotensin 2?
Left ventricular hypertrophy
Fibrosis
Remodelling
Apoptosis
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How does angiotensin 2 play an essential role in end organ damage in the brain and blood vessels?
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What is the end organ damage associated with the kidneys caused by angiotensin 2?
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What are contraindications of ACEI?
–Renal artery stenosis
–Renal failure
–Hyperkalaemia
What are the adverse drug reactions?
Cough
First dose hypotension
Taste disturbance
Renal impairment
Angioneurotic oedema (rapid swelling (edema) of the dermis, subcutaneous tissue, mucosa and submucosal tissues)
What are the relevant drug drug interactinos for ACEi?
NSAIDs
- Precipitate acute renal failure
Potassium supplements
- Hyperkalaemia
Potassium sparing diuretics
- Hyperkalaemia
What is conn’s syndrome?
Having too much aldosterone - renin levels are reduced. Features hypertension as symptom. Causes are increaed size of adrenal glands where aldosterone is produced or adenoma. Other uncommon causes include adrenal cancer and an inherited disorder called familial hyperaldosteronism
Give examples of angiotensin 2 antagonists (ARB)
•LOSARTAN, VALSARTAN, CANDESARTAN, IRBESARTAN
What receptor do ARB’s block?
angiotensin II antagonists competitively block actions of angiotensin II at angiotensin AT1 receptor
What is the advantage of ABR’s over ACEI’s?
No cough
What are the two types of calcium channel blocker?
Vasodilator
Rate limiting
What are two examples of vasodilator caclium channel blockers?
Amlodipine/Felodipine
What are two examples of rate limiting calcium channel blockers?
Verapamil/Diltiazem
How do CCB’s work?
–blocking the L type calcium channels (voltage type) (responsible for non-pacemaker action potential and pace maker cells - but not pace maker potential (pre-potential) which is down to the T calcium channels.
–selectivity between vascular and cardiac L type channels
–relaxing large and small arteries and reducing peripheral resistance
–reducing cardiac output
What are vasodilating CCB’s the antihypertensive choice for?
–over 55years.
–women of child baring age
Compliance is high,
Benefit in the elderly patient with systolic Hypertension
Rarely cause postural hypotension
What are contraindications for CCB’s?
Acute MI
Heart Failure, bradycardia (rate limiting CCB’s)
What are the adverse drug reactions for CCB’s?
–Flushing
–Headache
–Ankle oedema
–Indigestion and reflux oesophagitis
What are teh side effects of rate limiting calcium channel blockers?
–Bradycardia
–Constipation
What are common thiazide type diuretics?
Indapamide, Clortalidone
Who are thiazide type diuretics commonly the first line treatment for?
Commonly the first line treatment in mild-moderate hypertension in Afro-Caribbean
Can thiazides be used in combination with any other antihypertensive agents?
Yes all
What is another benefit of Thiazide type diuretics
•Proven benefit in stoke and MI reduction
What are the adverse drug reactions for thiazide type diuretics?
–ADR not common but include gout and impotence.
What are the less commonly used agents?
Alpha-adrenoceptor antagonists
–Doxazosin
Centrally acting agents
–Methyldopa
–Moxonidine
Vasodilators
–Hydralazine
–Minoxidil
What might you prescribe to young people who can’t tolerate other drugs?
Doxazosin
Alpha-adrenoceptor antagonists
What is the mechanism of doxazosin?
–Selectively block post synaptic a1-adrenoceptors
–Oppose vascular smooth muscle contraction in arteries – causes dilation
IT IS AN Alpha-adrenoceptor antagonists
What are the adverse reactions of doxazosin (an Alpha-adrenoceptor antagonists)?
–First dose hypotension
–Dizziness
–Dry mouth
–Headache
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What might you prescrive to a pregnant woman?
Methyldopa - cantrally acting agent
What is the mechanism for methyldopa?
Converted to a-methylnoradrenaline which acts on CNS a-adrenoceptors which decrease central sympathetic outflow
What are the adverse drug reactions for methyldopa?
–Sedation and drowsiness
–Dry mouth and nasal congestion
–Orthostatic hypotension
Give an example of a centrally acting imidazoline agonist
Moxonidine
Common treatment regime
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Standard regime for female or child
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Second most common cause of maternal and fetal death?
Hypertension during pregnancy
What is a common risk factor for preeclampsia?
•existing Primary Hypertension
How does blood pressure change during normal pregnancy?
Falls
What is the likely cause of hypertension brought on during pregnancy where there is no proteinuria?
–Gestational Hypertension.
What is the likely cause of hypertension brought on during pregnancy where there is proteinuria?
Preeclampsia
What are the recommended drugs for pregnant women?
–Not ACE or ARB
–Nifedipine MR (modified release) - immediate release is bad
Methyl dopa,
Atenolol (beta blocker) (not liscensed but doesn’t have a high first pass metabolism),
Labetalol (undergoes major first pass metaabolism – metabolism can be really high in pregnant women – so dose can be massive – poor prediction of blood pressure)
•During Pregnancy
–add thiazide diuretic and/or amlodipine.
What are the medications for preeclampsia?
•intravenous esmolol, labetalol, hydralazine (last two are beta blockers)