Hypertension Therapy Flashcards
What do you need to identify before starting hypertension treatment?
True hypertension (from white coat hypertension) - use ambulatory blood pressure monitoring (ABPM) or home blood pressure monitoring (HBPM)
What should be looked for and included in assessing risk of hypertension?
Previous MI, stroke or IHD Smoking Diabetes mellitus Hypercholesterolaemia Family history
What tests should be done to assess for potential end organ damage from hypertension?
ECG for LVH Echocardiogram for LVH Urine albumin to creatinine ratio for proteinuria Renal ultrasound for kidney damage eGFR for kidney function
What treatable causes of hypertension should be screened for?
Renal artery stenosis
Cushing’s disease
Conn’s syndrome
Sleep apnoea
What tools are available for risk assessment of hypertension?
Assign Risk Calculator
Q Risk
What does the BHS suggest as a target BP for hypertension treatment?
< 135/85mmHg
When should treatment of hypertension be started?
When overall CVD risk is 20%/10 years
What are the main reasons for treating hypertension?
Reduce cerebrovascular disease by 40-50%
Reduce MI by 16-30%
What is the treatment approach used for hypertension?
Stepped approach - do not continuously change medication, add new medication to current therapy until target BP is achieved
Low doses of several drugs
When should antihypertensive drug treatment be offered to people under 80 years old with ABPM > 135/85?
When they have one or more of; Target organ damage Established cardiovascular disease Renal disease Diabetes 10 year cardiovascular risk equivalent to 20% or greater
When should people with stage 2 hypertension be offered antihypertensive drug treatment?
Antihypertensive drug treatment should be offered to people of any age with stage 2 hypertension
When is specialist evaluation necessary in hypertension?
For people aged under 40 years with stage 1 hypertension or greater - evaluation of secondary causes and a more detailed assessment of potential target organ damage is necessary
What should be the approach to antihypertensive drug treatment in people over 80 years old?
Offer the same antihypertensive drug treatment as people aged 55-80, but take into account any co-morbidities
Blood pressure target will be different at 145/85mmHg
What should be the approach to treatment of white coat hypertension?
Consider ABPM or HBPM as an adjunct to clinical blood pressure measurements to monitor the response to antihypertensive treatment with lifestyle modification or drugs
What is stage 1 treatment of hypertension for people aged over 55 years?
Offer calcium channel blocker
If not suitable offer thiazide like diuretic
What is stage 1 treatment of hypertension for black people of African or Caribbean family origin of any age?
Offer calcium channel blocker
If not suitable offer thiazide like diuretic
When might a calcium channel blocker not be suitable?
Oedema
Intolerance
Evidence of heart failure
What is stage 1 treatment of hypertension for people under 55 years?
ACEI or ARB
These should not be offered to people of African or Caribbean family origin or to women of child-bearing age
What is step 2 treatment of hypertension?
Add a thiazide like diuretic to the existing CCB, ACEI or ARB
What is step 3 treatment of hypertension?
Combine CCB, ACE/ARB and thiazide like diuretic
What is step 4 treatment of hypertension?
Treatment of resistant hypertension
Consider further diuretic therapy with low-dose spironolactone if blood potassium level is 4.5mmol/l or lower
Consider high-dose thiazide-like diuretic if blood potassium level is higher than 4.5mmol/l
When might an ACEI and ARB both be used?
In young people where one is not sufficient in controlling BP
Give an example of an angiotensin converting enzyme inhibitor
Ramipril
Perindopril
How do ACEIs work?
Competitively inhibit the actions of angiotensin converting enzyme
Interfere with pathophysiology of coronary ischaemia and renal insufficiency through blockade of the renin-angiotensin system
What is the function of angiotensin converting enzyme?
Converts angiotensin I to active angiotensin II
What is the function of angiotensin II?
Potent vasoconstrictor and hypertrophic agent - plays a central role in organ damage
What are the contraindications to ACEI use?
Renal artery stenosis
Renal failure
Hyperkalaemia
What are the possible adverse drug reactions from ACEI use?
Cough First dose hypotension Taste disturbance Renal impairment Angioneurotic oedema
What are the potential drug-drug interactions from ACEI use?
NSAIDs - precipitate acute renal failure
Potassium supplements - hyperkalaemia
Potassium sparing diuretics - hyperkalaemia
Give an example of an angiotensin II antagonist
Losartan
Valsartan
Candesartan
Irbesartan
How do ARBs work?
Competitively block the actions of angiotensin II at the angiotensin AT1 receptor
What is the advantage of ARBs over ACEIs in terms of adverse drug reactions?
No cough
Give an example of a vasodilating calcium channel blocker
Amlodipine
Felodipine
Give an example of a rate-limiting calcium channel blocker
Verapamil
Diltiazem
How do CCBs work?
Block L-type calcium channels
Selectivity between vascular and cardiac L-type channels
Relax large and small arteries and reduce peripheral resistance
Reduce cardiac output
When are vasodilation CCBs the antihypertensive of choice?
In over 55 year olds
Women of child-bearing age
What is a rare adverse drug effect of CCBs?
Postural hypotension
What are the contraindications for CCB use?
Acute MI
Heart failure
Bradycardia
What are the potential adverse drug reactions of CCBs?
Flushing
Headache
Ankle oedema
Indigestion and reflux oesophagitis
Rate-limiting agents also cause;
Bradycardia
Constipation
Give an example of a thiazide-like diuretic
Indapamide
Clortalidone
When are thiazide-like diuretics commonly the first line treatment?
In mild-moderate hypertension in Afro-Caribbeans
In what conditions do thiazide like diuretics have a proven benefit?
Stroke and myocardial infarction reduction
What is the mechanism of action of thiazide-like diuretics
Block reabsorption of sodium
Enhance urinary sodium loss
What are the possible adverse drug reactions of thiazide like diuretics?
Gout
Impotence
What are some agents which can be used in hypertension treatment but which are less commonly used?
Alpha-adrenoceptor antagonists e.g. doxazosin
Centrally acting agents e.g. Methyldopa, moxonidine
Vasodilators e.g. hydralazine, minoxidil
How do alpha adrenoceptor antagonists work?
Selectively block post-synaptic alpha-1 adrenoceptors
Oppose smooth muscle contraction in arteries
What are potential adverse drug reactions of alpha adrenoceptor antagonists?
First dose hypotension
Dizziness
Dry mouth
Headache
What is the main use of centrally acting agents?
Main use in treatment of hypertension of pregnancy
How do centrally acting agents work?
Converted to alpha-methylnoradrenaline which acts on CNS alpha adrenoceptors which decrease central sympathetic flow
What are the potential adverse drug reactions of centrally acting agents?
Sedation and drowsiness
Dry mouth and nasal congestion
Orthostatic hypotension
What is the common starting regime for hypertension treatment in over 55s?
Start CCB
Add thiazide like diuretic if no or incomplete effect
Add ACEI if no or incomplete effect
Add beta-blocker if no or incomplete effect
Add one of less commonly used agents if still incomplete effect
What is the common starting regime for hypertension treatment in the young?
Start ACEI
Start CCB or beta-blocker if female of child-bearing age
Add ACEI if incomplete effect
Add beta-blocker if incomplete effect
Add one of the less commonly used agents if still incomplete effect
Why is it important to treat hypertension during pregnancy?
Second most common cause of maternal and foetal death
Common risk factor for pre-eclampsia
What is gestational hypertension?
BP rises and patient develops hypertension during pregnancy, no proteinuria
What is pre-eclampsia?
Where BP rises severely from about 20 weeks to a BP or 140-90mmHg combined with proteinuria of > 300mg/24 hours
What drugs should not be given to treat hypertension in pregnancy?
ACEI
ARB
What should treatment of pre-eclampsia involve?
Thiazide like diuretic and/or amlodipine
IV esmolol, labetalol or hydralazine
How is hypertension defined in children?
Statistically
Systolic or diastolic BP ≥ 95th centile for gender, age and height on three or more separate occasions
What is stage 1 hypertension in children?
BPs from the 95th-99th percentile plus 5mmHg
What is stage 2 hypertension in children?
BP above the 99th percentile plus 5mmHg
Between what centiles should blood pressure be considered high-normal for age?
Between 91st and 98th
What is the prevalence of pre-hypertension and hypertension in children?
Pre-hypertension 3-10%
Hypertension 0.1-3%
What is childhood hypertension associated with?
LVH
Decreased vascular responsiveness
Increased carotid artery intimal medial thickness
Reduced GFR
Increased atheroma deposition
Reduced cognitive scores in hypertensive children
What are the commonest causes of hypertension in newborn infants?
Renal artery stenosis
Renal artery thrombosis
Congenital renal malformation
Coarctation of the aorta
What are the commonest causes of hypertension in infants/children up to 6 years old?
Renal parenchymal disease
Coarctation of the aorta
Renal artery stenosis
What are the commonest causes of hypertension in 6-10 year olds?
Renal parenchymal disease
Renal artery stenosis
Primary hypertension
What are the commonest causes of hypertension in 10-18 year olds?
Primary hypertension
Renal parenchymal disease
What is accelerated hypertension?
Increase in BP to levels ≥ 180mmHg systolic and ≥ 110mmHg diastolic resulting in target organ damage e.g. neurological, cardiovascular or renal damage plus grade III retinal changes
What is malignant hypertension?
The term malignant hypertension is reserved for cases where papilloedema grade IV Randal changes are present
What is hypertensive urgency?
Severe hypertension with no evidence of target organ damage
What is accelerated hypertension associated with?
Existing diagnosis of hypertension and prescribed antihypertensive agents
Poor BP control prior to presentation
Lack of primary care contact and lack of healthcare in general
Non-Adherence to medication
Use of illicit drugs
What do NHLBI and ESH/ESC guidelines recommend in hypertensive emergencies?
Reducing mean arterial pressure by by ≤ 25% for the first hour and then to 160/100-110mmHg by 2-6 hours, with subsequent gradual normalisation over 24-48 hours
How should isolated large BP elevations (often associated with treatment discontinuation or reduction and with anxiety) be treated?
Should not be considered as an emergency but should be treated by reinstitution or intensification of drug therapy and treatment of anxiety
What should not be done in treatment of a hypertensive emergency?
Do not reduce BP suddenly and excessiblef
Do not use sublingual medication
Do not use rapidly acting nifedipine or ACEI
Do not use intermitting as required therapy (oral or IV)
Do not use IV hydralazine
Do not use sodium nitroprusside
What will excessive correction of BP result in?
Further reduced organ perfection and multi-organ infarction
How are patients with a hypertensive emergency best managed?
With a continuous infusion of a short acting, titratable antihypertensive agent
What is the immediate goal in treatment of a hypertensive emergency?
To reduce DBP by 15-20% or to about 100 mmHg over a period of 30-60 minutes
How should a hypertensive emergency be managed?
Set a 2 hour and 6 hour BP target to be achieved
Stabilise with IV agent(s) then initiate oral therapy and titrate IV agent(s) down slowly
Assess fluid status
How should pulmonary oedema in a hypertensive emergency be managed?
IV GTN started at low dose the up-titrate
IV furosemide
Initiate oral medication e.g. amlodipine 5mg once patient is stable
How should encephalopathy in a hypertensive emergency be treated?
IV nicardipine 5mg/hour, elevidipine 1-2mg/hour
IV labetalol 0.5-2mg/min
IV esmolol 0.5-1mg/kg loading dose over 1 min then 50mg/kg/min and up to 300mgkg/min
Initiate oral medication such as amlodipine once stable
