Hypertension Therapy Flashcards
How is the diagnosis of hypertension made?
- ABPM ambulatory blood pressure monitoring
- HBPM home blood pressure monitoring
Stage 1 hypertension
- Clinical blood pressure is 140/90 mmHg or higher
- ABPM daytime average 135/85 mmHg or higher
Stage 2 hypertension
- Clinic blood pressure is 160/100 mmHg or higher
- ABPM daytime average 150/95 mmHg or higher
Severe hypertension
Clinic systolic blood pressure is 180 mmHg or higher or diastolic blood pressure is 110mmHg or higher
What factors are considered when assessing risk of hypertension?
- Previous MI, stroke, IHD
- Smoking
- Diabetes mellitus
- Hypercholesterolemia
- Family History
- Physical Examination
How is end organ damage assessed?
- ECG: LVH
- ECHO: LVH
- Proteinuria: ACR
- Kidney: renal ultrasound
- Renal function: eGFR
What treatable causes of hypertension are screened for?
- Renal artery stenosis/ FMD
- Cushings disease
- Conn’s syndrome
- Sleep apnoea
What is used to assess risk correctly?
Assign risk calculator/ Q-risk
What should you do once you have assessed a patient’s risk?
Set a target blood pressure
What does the BHS suggest the target blood pressure should be?
<135/80-85 mmHg
When should treatment be started?
When overall CVD risk of 20%/10 yrs
Why do we treat hypertension?
- Reduce cerebrovascular disease by 40-50%
- Reduce MI by 16-30%
What is the general approach in the treatment of hypertension?
- Stepped approach
- Use low doses of several drugs
- This approach minimises adverse events and maximises patient compliance
How is a stepped approach achieved?
- Do not continuously change antihypertensive medication
- Add new medication to current therapy until the target BP is achieved
What are the go to drugs for the young?
High renin:
-ACE inhibitors/ ARB
What are the go to drugs for the elderly?
Low renin:
- Calcium channel blocker
- Thiazide type diuretic
Who with stage 1 hypertension should be offered treatment?
People aged under 80 yrs old with ABPM >135/85 with 1+ of :
- Target organ damage
- Established CVD
- Renal disease
- Diabetes
- A 10 yr CV risk equivalent to 20% or greater
Who with stage 2 hypertension should be offered treatment?
- ABPM >150/95 mmHg
- Any age
What should you do if faced with a patient under 40 and with stage 1 or greater hypertension?
Seek specialist evaluation of secondary causes of hypertension and a more detailed assessment of potential target organ damage.
What is the blood pressure target in the over 80s?
<145/85mmHg
How does the treatment compare between 80+ and 55-80 yrs old?
Offer the same hypertensive treatment, taking into account any co-morbidities
What should you do if people are identified as having ‘white coat effect’?
Consider ABPM or HBPM as adjunct to clinic BP measurements to monitor the response to antihypertensive treatment with lifestyle modification or drugs
Who should be offered CCB as step 1 antihypertensive treatment?
- Age >55years
- Black people of African descent or Caribbean family origin
Why may a CCB not be suitable as stage 1 antihypertensive?
- Oedema
- Intolerance
- Evidence of heart failure
- High risk of heart failure
What should be offered to those unable to have CCB as stage 1 antihypertensive treatment?
Thiazide like diuretic
Who should be offered ACEI/ARB as stage 1 antihypertensive?
-Age<55years
Who should not have ACEI/ARB?
- Afro-Caribbean
- Women of child bearing age
What is step 2 in hypertension treatment?
-Add thiazide type diuretic such as clortalidone or indapamide to CCB or ACEI/ARB
What is step 3 in hypertension treatment?
Add CCB, ACEI, Diuretic together
Who receives step 4 treatment?
Resistant hypertension
What is step 4 treatment?
- Consider further diuretic therapy with low dose spironolactone if blood potassium is 4.5mmol/l or lower
- Consider higher dose thiazide like diuretic if the blood potassium is more than 4.5mmol/l
Whys should caution be taken with those with reduced GFR and diuretics?
They have increased risk of hyperkalaemia
If there is no contraindications what treatment should someone over 55 be started on?
CCB
If the is no contraindications what treatment should a young person be started on?
- ACEI or ARB
- If single agent doesn’t work then use 2
Give 2 examples of ACEI.
- Ramipril
- Perindopril
What do ACEI do?
-Competitively inhibit the actions of ACE
-ACE converts angiotensin I to active
angiotensin II
-Angiotensin II is a potent vasoconstrictor and hypertrophic agent
What does angiotensin II play a central role in?
Organ damage
What are the contraindications for ACEI?
- Renal artery stenosis
- Renal failure
- Hyperkalaemia
What are the adverse drug reactions of ACEI?
- Cough
- First dose hypotension
- Taste disturbance
- Renal impairment
- Angioneurotic oedema
What drugs do ACEI interact with?
- NSAIDs
- Potassium supplements
- Potassium sparing diuretics
ACEI and NSAIDs
Precipitate acute renal failure
ACEI and potassium supplements
Hyperkalaemia
ACEI and potassium sparing diuretics
Hyperkalaemia
Give 4 examples of ARB?
- Losartann
- Valsartan
- Candesartan
- Irbesartan
What is another name for ARB?
-Angiotensin II Antagonists
What do ARBs do?
-Angiotensin II antagonists competitively block the actions of angiotensin II at the angiotensin AT1 receptor
What is the advantage of ARB over ACEI?
No cough
Give 2 examples of vasodilator CCBs.
- Amlodipine
- Felodipine
Give 2 examples of rate limiting CCBs
- Verapamil
- Diltiazem
How do CCBs work?
- Block the L type calcium channels
- Selectivity between vascular and cardiac L type channels
- Relax large and small arteries and reduce peripheral resistance
- Reduce CO
Vasodilating CCBs are the treatment of choice in:
- Age>55 years
- Women of child bearing age
What are the advantages of CCBs?
- Compliance is high
- Benefit in the elderly patient with systolic hypertension
- Rarely cause postural hypotension
What are the contraindications for CCBs?
- Acute MI
- Heart failure
- Bradycardia
What are the adverse drug reactions for CCBs?
- Flushing
- Ankle oedema
- Headache
- Indigestion and reflux oesophagitis
What can the rate limiting CCBs cause?
- Bradycardia
- Constipation
Give 2 examples of thiazide type diuretics.
- Indapamide
- Clortalidone
Who are thiazide type diuretics used in as first line treatment?
Mild-moderate hypertension in Afro-Caribbean
How can thiazide like diuretics be used in combination therapies?
Can be used in combination with any other agents
What is there proven benefit for in for thiazide type diuretics?
Stroke and MI reduction
What is the mechanism of action for thiazide type diuretics?
Block reabsorption od sodium and enhance urinary sodium loss
What are the adverse drug reactions for thiazide type diuretics?
- Not common
- Gout
- Impotence
What are some less commonly used agents?
- Alpha adrenorecptor antagonists
- Centrally acting agents
- Vasodilators
Give an example of a alpha adrenoreceptor antagonist.
Doxazosin
Give 2 examples of centrally acting agents.
- Methyldopa
- Moxonidine
Give 2 examples of vasodilators
- Hydralazine
- Minoxidil
What do alpha adrenoreceptors do?
- Selectively block post synaptic a1 adrenoreceptors
- Oppose vascular smooth muscle contraction
What are the adverse drug reactions for alpha adrenoreceptors?
- First dose hypotension
- Dizziness
- Dry mouth
- Headache
What is the main use of methyldopa?
Treatment of hypertension of pregnancy
How does methyldopa work?
Converted to a-methylnoradrenaline which acts on CNS a adrenoreceptors which decrease central sympathetic outflow
What are the adverse drug reactions for methyldopa?
- Sedation and drowsiness
- Dry mouth and nasal congestion
- Orthostatic hypotension
What is moxonidine?
Centrally acting imidazoline agonist
What is the common treatment regime for age>55?
- Start CCB
- Add thiazide type diuretic
- Add ACEI
- Add B blocker
- Add less commonly used agent
What is the common treatment regime for <55 years?
- Start ACEI (women of child bearing age CCB or B blocker)
- Add thiazide type diuretic
- Add CCB
- Add B blocker
- Add less commonly used agent
What is a common risk factor for pre-eclampsia?
Primary hypertension
What happens to BP during normal pregnancy?
Falls
Gestational hypertension
HT develops in pregnancy due to BP rise with no proteinuria
Pre-eclampsia
HT develops from around 20 week in pregnancy due to severe BP rise with proteinuria
What is important to remember when treating HT in pregnancy?
Many medications are teratogenic
What drugs are safe to use pre-pregnancy?
- NO ACEI or ARB
- Nifedipine MR
- Methyldopa
- Atenolol
- Labetalol
What drugs should be used during pregnancy?
Add thiazide diuretic and/or amlodipine
How is pre-eclampsia treated?
- Treatment for HT in pregnancy
- Plus IV esmolol, labetalol, hydralazine
- Deliver the baby
Hypertension in children UK
Using UK population data BP greater than or equal to 98th centile represents HT
High normal BP children in the UK
Between the 91st and 98th centiles
What is the prevalence of pre-hypertension in children?
3-10%
What is the prevalence of hypertension in children?
0.1-3% depending on age and ethnicity
What can childhood hypertension lead to?
- Adult hypertension
- Target organ damage
What end organ damage is childhood hypertension associated with?
- Left ventricular hypertrophy
- Decreased vascular responsiveness
- Increased carotid artery intimal medical thickness
- Reduced GFR
- Increased atheroma deposition
- Reduced cognitive scores
What are the commonest causes of hypertension in new-borns?
- Renal artery stenosis
- Renal artery thrombosis
- Congenital renal malformations
- Coarctation
What are the commonest causes of hypertension in infants (6years)?
- Renal parenchymal disease
- Coarctation
- Renal artery stenosis
What are the commonest causes of hypertension in children aged 6-10 years?
- Primary hypertension
- Renal artery stenosis
- Renal parenchymal disease
What are the commonest causes of hypertension in children aged 10-18 years?
- Primary hypertension
- Renal parenchymal disease
Why is there an increase in primary hypertension?
- Obesity
- ‘The Glasgow Salad’
- Lack of exercise
Accelerated hypertension
- Increase in BP to levels >180mmHg systolic and >110 diastolic resulting in target organ damage such as neurological, cardiovascular or renal damage plus grade III retinal changes
- A recent significant increase over baseline BP that is associated with target organ damage
Malignant hypertension
Usually reserved for cases where papilloedema grade IV fundal changes are present
Hypertensive urgency
Severe hypertension with no evidences of target organ damage
What is accelerated hypertension associated with?
- Non adherence to medication
- An existing diagnosis of HTN and prescribed antihypertensive agents
- Poor BP control prior to presentation
- A lack of primary care contact. Lack of healthcare in general
- Illicit drug use
How should hypertensive urgency be treated?
Should not be considered an emergency but treated by reinstitution or intensification of drug therapy
How are hypertensive emergencies treated?
-Reduction of MAP by less than 25% in 1st hour then to 160/100-1220mmHg by 2-6 hrs with subsequent gradual normalisation over 24-48hrs
What should not be done in a hypertensive emergency?
- Reduce BP suddenly and excessively
- Use sublingual medication
- Use rapidly acting nifedipine or ACEI
- Use intermittent as required therapy, oral or IV
- Use IV Hydralazine
- Use sodium nitroprusside
What will excessive correction of BP do?
-Further reduce organ perfusion and produce multi-organ infarction
How are patients with hypertensive emergencies best managed?
With continuous infusion of short acting, titrable antihypertensive agent
What type of administration should be avoided at all times?
Sublingual and IM
What is the immediate goal in the treatment of accelerated hypertension?
Reduce DBP by 15-20% or to about 110mmHg over a 30-60 min period
What should be set in the treatment of accelerated hypertension?
A 2h and 6h BP target to achieve
What can be done after patients with accelerated hypertension are stabilised?
- Oral therapy can be initiated and the IV agents slowly titrated down
- Assess fluid status
What agents should be used if there is pulmonary oedema?
- IV GTN
- IV furosemide
- Amlodipine once stable
What agents should be used if there is encephalopathy?
- IV nicardipine, clevidipine
- IV labetalol
- IV esmolol
- Amlodipine once stable
What problems with treatment are there?
- Late
- Excessive BP reduction
- Treatment failure
- Adverse events
- Multi-organ infarction due to profound hypotension
What are the prognostic indicators for accelerated hypertension?
- Plasma creatinine
- Follow up BP
