5 Hypertension and Heart Failure Flashcards
How is hypertension defined? (NICE guidelines)
NICE Hypertension= BP >140/90 mmHg
Elevation in blood pressure that is asssociated with an increase in risk of some harm
Elevated blood pressure that treated will do more good than harm
What are the different types of hypertension? (4)
- Essential/primary/idiopathic
- Secondary (to other pathology eg Pheochromocytoma)
- Isolated systolic/diastolic
- White coat/clinic (elevation of blood pressure whilst at clinic)
- need to be careful to not overdiagnose
Outline the best practice for measuring blood pressure?
- Patient sat, relaxed, arm supported
- Take pressure from both arms
- If >15mmHg difference between arms, repeat measurement
- Use arm with higher reading
What might be classes as a hypertensive emergency? What are the clinical signs?
Hypertensive emergency= BP >180/120 + clinical signs
What BPs are classed as hypertension for:
- <80 year olds
- >80 year olds
- type 1 diabetics
- <80 year olds= 140/90
- >80 year olds= 150/90
- type 1 diabetics= 135/85
What are the different stages of hypertension (give BP values)
What is defined as prehypertension? What lifestyle changes should be recommended to patients who are prehypertensive?
Prehypertension= >120/80 and < 140/90 mmHg
- Promotion of regular exercise
- Healthy diet
- Limit/reduce alcohol intake
- Smoking cessation
- Reduce dietary sodium
- Discourage excessive caffeine consumption
What are the main therapeutic agents for treating primary hyertension? (4)
- ACE inhibitors (Angiotensin converting enzyme inhibitors)
- ARBs (Angiotensin receptor blockers
- CCBs (Calcium channel blockers)
- Diuretics (eg thiazides)
How do ACE inhibitors aim to reduce blood pressure? (ie what mechanisms)
Limit conversion of Angiotensin I to Angiotensin II
Reduce angiotensin II effects:
- Vasodilation
- Reduce aldosterone release (increase Na+ and H2O excretion)
- Reduce ADH (vasopressin) release (increase H2O excretion)
- Reduce cell growth and proliferation
Can angiotensin II be produced from angiotensin I independently of ACE?
Yes- by chymases
Give the names of 2 ACE inhibitors.
naproxen= NSAID
Explain why a patient may get a dry cough as a result of taking lisinopril or ramipril.
- Bradykinin is a substrate for ACE aswell as ACEi.
- Use of ACEi potentiates bradykinin
- Bradykinin causes vasodilation via NOS/NO and prostacyclin (vasodilator)
- Dry cough due to build up of bradykinin
What are some of the contraindications of ACE inhibitors? (5) Who should they not be given to? (3)
Contraindications
- Hypotension
- Dry cough
- Hyperkalaemia (low aldosterone)
- Renal failure (renal artery stenosis)
- AKD
Who should we not give ACE inhibitors to?
- Patients w./ CKD
- Pregnancy
- Breastfeeding
What are some of the important drug interactions with ACEi to note?
- Drugs that increase K+
- NSAIDs
- Other antihypertensive agents
Give 2 examples of angiotensin II receptor blockers (ARBs).
- Candesartan
- Losartan
How do ARBs act to reduce BP?
(ARBs= Angiotensin-II blockers= AT1 Receptor blockers)
Angiotensin II acts on AT1 and AT2 receptors
Directly target AT1 receptors (more effective at inhibiting Angiotensin II mediated vasoconstriction - chymase production)
Why do ARBs not cause a dry cough or angioedema but ACE inhibitors do?
Angioedema is an area of swelling of the lower layer of skin and tissue just under the skin or mucous membranes
ARBs have no effect on bradykinin
Less effective in low- renin hypertensives
What are some of the contraindications of ARBs inhibitors? (3) Who should they not be given to? (3)
Contraindications
- Hyperkalaemia (low aldosterone)
- Renal failure (renal artery stenosis)
- AKD
Who should we not give ACE inhibitors to?
- Patients w./ CKD
- Pregnancy
- Breastfeeding
What are some of the important drug interactions with ARBs to note?
- Drugs that increase K+
- NSAIDs
- Other antihypertensive agents
How do CCBs (calcium channel blockers) work to reduce hypertension?
CCBs- target calcium initiated smooth muscle contraction
Different classes (3) interact with different sites on α1 subunit of VOCC
Outline the mechanism/site of action of the 3 classes of CCBs which are used to treat hypertension:
- State the names of drugs in each class
- State how they work
- Which class is the first line CCB in hypertension
- Which drug has selectvity for cerebral vasculature
- Which drug is use to treat arrythmia and angina
What are some of the side effects of dihydropyridines and who should it not be given to (contraindications)?
Side effects:
Ankle swelling
Flushing
Headaches
Palpitations
Contraindications:
Unstable angina
Severe aortic stenosis
What are the 2 important drug interactions to know for the dihydropyridine class of CCBs?
- Amlodipine + simvastatin - increase effect of statin
- Other antihypertensive agents
What are some of the side effects of phenylalkylamines and who should it not be given to (contraindications)?
Side effects:
- Constipation
- Bradycardia (iv)
- Heart block
- Cardiac failure
Contraindications:
- Poor left ventricular function
- AV nodal conduction delay
What are 3 important drug interactions with phenylalkylamines that we should be aware of?
- β-blockers
- Other hypertensives
- Other antiarrythmics
Give the name of a thiazide diuretic and a thiazide like diuretic.
Thiazide diuretic: bendroflumethiazide
Thiazide like diuretic: indapamide
What are some of the side effect of thiazides and what are their 2 important drug interactions?
Side effects:
- Hypokalaemia
- Hyponatraemia
- Impaired glucose tolerance
- Increased cholesterol and triglyceride levels
- Gout
- Increased urea and uric acid levels
Interations:
- NSAIDs
- Potassium lowering drugs
Thiazides are more likely to be chosen to treat hypertension over CCBs if the patient has what sign/symptom?
Oedema
Why are CCBs used in the first instances to treat hypertension in over 55s and those of black African and Caribbean groups?
These populations have low levels of renin in first place- not ideal target system in first instance (RAAS)
Why are ACE inhibitors or ARBs the first line treatment for hypertension secondary to type 2 diabetes irrespective of age or ethnicity?
ACEis and ARBs have added benefits at kidneys
- Decrease incidence of diabetic nephropathy and CKD w./proteinuria
- Dilation of efferent glomerular arteriole
- Reduced intraglomerular pressure
- Dilation of efferent glomerular arteriole
What drugs can be used to treat resistant hypertension (stage 4)? (3) Which of these should be used if blood potassium is >4.5 mmol/l and if blood potassium is <4.5 mmol/l?
How does spironolactone work? What are its contraindications (2) and what are its important drug interactions to consider?
Sprionolactone= aldosterone antoagonist–> stops action of aldosterone at ENaC and also blocks ROMK
Contraindications:
- Hyperkalaemia
- Addison’s
Interactions:
- Other K+ increasing drugs
- ACE inhibitors
- ARBs
Name 3 β-adrenoreceptor blockers (used to treat hypertension) and explain how beta blockers work to reduce blood pressure.
-
Labetalol (β1, β2 and α1)
- Used: preganncy and hypertensive emergencies)
- Bisoprolol (β1)
- Metoprolol (β1)
How do they work?
- Block noradrenaline
- Decrease sympathetic tone
- Reduce CO
- Reduce release of renin in kidneys (release= partly regulated by β1- adrenoreceptors)
- ie REDUCE SYMPATHETIC OUTFLOW
With relation to β-blockers give the:
Side effects (5)
Contraindications (4)
Interactions (1)
Side effects:
- Bronchospasm
- Heart block
- Raynaud’s
- Lethargy
- Impotence
Contraindications:
- Asthma
- COPD
- Haemodynamic instability
- Hepatic failure
Interactions:
- Non-dihydropyridine CCBs
- Verapamil
- Diltiazem
Name 2 α-blocker and describe how they work to treat hypertension. Apart from hypertension what else are they used to treat?
- Doxazosin
- Tamsulosin
How does it work?
- Selective antagonism- α-1 adrenoreceptors
- Reduce peripheral vascular resistance
Tamsulosin also used to treat symptoms of BPH
State the main contraindications and interactions from α-adrenoreceptor blockers.
Contraindications:
- Postural hypotension
Interactions:
- Dihydropyridien CCBs- oedema
Useful diagram showing neurohormonal response attempting to compensate for hypertension leading to further pathology:
Identify some drugs used to treat and manage heart failure:
Outline the approach to the management of heart failure. (Aims and how is this done)
