Hypertension Therapy Flashcards
How is true hypertension diagnosed?
- ABPM - HBPM (home)
How is risk of hypertension assessed?
- Previous MI, stroke, IHD - Smoker - Diabetes - Hypercholesterolaemia - Family history (familial HCRM) - Physical exam
What would you do to assess the end organ damage of the heart?
- ECG - Echocardiogram
What would you do to assess the end organ damage of the kidneys?
- Proteinuria - Renal ultrasound - Renal function (glomerular filtration)
How would the cause of the hypertension be tested?
Screen for common causes such as endocrine or renal artery stenosis
What does LVH stand for?
Left ventricular hypertrophy
What does the ECG show?
Left ventricular hypertrophy can be seen by the inversion of the t wave
After you have calculated the patients risk what should you next do?
Choose a target BP to reduce to
At what assign-score risk should treatment for CVD be given?
15-20%
How do we treat hypertension?
- Slow stepped approach
- Low doses of multiple drugs
Why are low doses of multiple hypertensives given?
Reduce side effects
What class are young people given when deciding hypertension therapy?
A (high renin)
What drugs are given for people with high renin?
ACE inhibitors
What class are elderly people put into for hypertension therapy?
C and D (low renin)
What drugs are used to treat C and D classes?
C - calcium channel blocker
D - thiazide - type diuretic
When should treatment of stage 1 hypertension of someone under the age of 80 be given?
If they have any of the following
- Organ damage
- CVD
- Renal disease
- Diabetes
- CVD risk of greater than 20%
Why is a thiazide-like diuretic sometimes offered in place of a calcium channel blocker?
- Intolerence
- Evidence or high risk of heart failure
What is added to the treatment of hypertension if CCB doesn’t reach intended BP?
- Thiazide-type diuretic such as clortalidone/indapamide
- ACEI
If desired BP isn’t reached after CCB and additions what is done?
- CCB
- ACEI
- Diuretic
All given at the same time
If all three drugs together what should be done?
- Further diuretic therapy with low dose spironolactone if K levels low
- Consider higher dose thiazide-like diuretic
What are examples of ACE inhibitors?
- RAMIPRIL
- Perindopril
What are the contraindictions of 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 (rapid swelling of the dermis)
What are the drug-drug interactions with ACEI?
- NSAIDs - acute renal failure
- Potassium supps - hyperkaelemia
- Potassium sparing diuretics - hyperkalaemia
What are ARB’s?
Angiotensin II antagonists
What is the advantage of ARB’s over ACEI?
No cough
What are the two common vasodilator calcium channel blockers?
- Amlodipine
- Felodipine
What are the 2 common rate limiting CCB?
- Verapamil
- Diltiazem
How do CCB’s work?
- Blocking L-type calcium channels
- Can be selective between vascular and cardiac L type channels
- Relaxes large and small arteris (TPR down)
- Reduces CO
What are the CCB’s contraindictions?
- Acute MI
- Heart failure, bradycardia
What are the adverse drug reactions of CCB’s?
- Flushing
- Headache
- Ankle oedema
- Ingestion and reflux oesophagitis
What can rate limiting agents (CCB’s) also cause?
- Bradycardia
- Constipation
Diagram showing CCB’s action
Notice how reducing calcium level will reduce contraction level
What are the 2 common thiazide type diuretics?
- Indapamide
- Clortalidone
Where do Thiazides work on in the nephron?
Distal tube
How do thiazide type diuretics work?
- Block reabsorption of sodium
- Enhance loss of sodium through urine
What are less commonly used antihypertensives?
- Alpha adrenoreceptor antagonists - Doxazosin
- Centrally acting agents - methyldopa, moxonidine
- Vasodilators - hyrdalazine, minoxidil
What is the mechanism of action of doxazosin?
- Block post synaptic alpha 1 adrenoreceptors
- Stop vascular smooth muscle contraction in arteries
What is the main use of methyldopa to treat hypertension?
In pregnancy
What does methyldopa do?
Acts on alpha receptors in the CNS to decrease sympathetic innervation
Take a patient at 55 years, this is your course of action
If over 55years of age
•Start CCB
–No or incomplete effect
•Add Thiazide-type diuretic
–Incomplete effect
•Add ACE inhibitor
–Still incomplete effect
•Add Beta-blocker
–Still incomplete effect
•Add one of the less commonly used agents
This is the course of action for a young hypertensive
- Start ACEI
- If female of child bearing age CCB or Beta Blocker
- No or incomplete effect
- Add Thiazide type diuretic
–Incomplete effect
•Add Calcium channel blocker
–Still incomplete effect
•Add Beta-blocker
–Still incomplete effect
•Add one of the less commonly used agents
What is the treatment for gestational hypertension?
- NO ACEI OR ARB
- Pre pregnancy - use nifedipine, methyldopa, atenolol, labetalol
- During pregnancy - add thiazide diuretic
What is the prevelence of childhood pre hypertension?
3-10%
What is typical end organ damage associated with childhood hypertension?
- LVH
- Decreased vascular response
- Increased carotid artery medial thickness
- Low GFR
- Increased atheroma deposits
- Reduced cognitive scores
What are the common causes of hypertension in newborn infants?
- Renal artery thrombosis
- Renal artery stenosis
- Congenital renal malformations
- Coarctication
What are the common causes of hypertension in infants?
- Renal parenchymal disease
- Coarctication
- Renal artery stenosis
Why is there an increase in primary childhood hypertension?
- Obesity
- Lack of exercise
Both very high at the moment
What is accelerated hypertension?
An increase in blood pressure (180/110) resulting in organ damage and retinal changes
What is malignant hypertension?
Cases where papilloedema (stage 4) fundal changes are present (optical disc swelling caused by increased cranial pressure)
What is accelerated hypertension associated with?
- Existing hypertension diagnosis
- Poor BP control
- POOR REACTION TO MEDICATION
WHAT NOT TO DO WITH HYPERTENSIVE PATIENTS
- Do not reduce BP suddenly and excessively.
- Do not use sublingual medication.
- Do not use rapidly acting nifedipine or ACEI.
- Do not use intermittent as required therapy, oral or IV.
- Do not use IV hydralazine
–5-20 minute lag before producing an erratic response
•Do not use sodium nitroprusside
–(coronary steal syndrome and increased intracranial pressure, cyanide toxicity)
