B.3 Treatment of Hypertension Flashcards
What lifestyle changes can be implemented in order to reduce hypertension?
Lifestyle changes play a central and primary role:
Reduce alcohol consumption (increases BP)
Weight reduction
Excess caffeine reduction
Increase fruits and oily fish in the diet
Increase exercise
Smoking cessation
Who should be treated with hypertensive drugs?
People with a clinic blood pressure value of >140/>90mmHg and a home reading of >135/>85mmHg
All patients with stage 2 should be treated
Patients with stage 1 that are less than 80 years old
Look at lecture slides
How do Angiotensin-Converting Enzyme Inhibitors (ACEi) work?
ACEi interferes with the renin-angiotensin-aldosterone system
It inhibits the conversion of angiotensin I in the lungs to angiotensin II.
This prevents vasoconstriction of arterial and venous
And the production of aldosterone leading to a reduction in salt and water retention, therefore, reduces circulatory volume.
Also promotes bradykinin
What is renin released by?
Juxtaglomerular cells in the kidney
What is angiotensinogen and where is it produced?
Acts as a precursor and produced in the liver
How does ACEi produce a cough?
ACEi inhibits the ACE enzyme which helps breakdown bradykinin and inhibiting this will mean that bradykinin can not be broken down
This stimulates a cough
What adverse effects are associated with ACEi?
Cough 10%
Increase K+ which governs resting membrane potential. (hyperkalaemia)
Changes to this can cause depolarisation
and abnormal electrical potential
Can lead to arrhythmias
Angioedema: swelling of eyelids and lips
In what condition should ACEi’s be avoided?
Renovascular disease
- Renin-dependent hypertension, ACEis lead to renal under perfusion and severe hypertension
May lead to worsening of renal function
Can ACEi lead to worsening of renal function and how should this be managed?
Yes, eGFR should be monitored before and during the use of ACEi’s (and plasma potassium levels should be monitored)
What is eGFR?
Estimated glomerular filtration rate is the best way to measure kidney function and determine the stage of kidney disease
ACEI’s are effective at the prevention of nephropathy in DM and may be agents of choice in patients with diabetes. T/F?
True
Give some examples of AT1 receptor antagonists
Candesartan, Losartan, Valsartan
What are AT1 receptor antagonists and how do they work on a pharmacological level?
A drug used to block the action of angiotensin II at the AT1 receptor.
Interferes with the RAAS, blocks AT1 receptors, therefore, inhibits the effects of AII, inhibiting vasoconstriction and production of aldosterone
Give an example of a calcium channel inhibitor (vasodilators)
Diltiazem, verapamil and dihydropyridines
Amlodipine, felodipine, nifedipine
How do calcium channel inhibitors work on a pharmacological level?
Inhibit voltage-operated Ca2+ channels on vascular smooth muscle
This leads to vasodilation and reduced BP
- Calcium channel inhibitor blocks the voltage-gated calcium channels on the vascular smooth muscle cells.
- This means that the vascular smooth muscle cell can not reach depolarisation
- This means that the vascular smooth muscle will not contract and remain dilated, reducing the BP
Name a thiazide-like diuretic
Indapamide and chlortalidone
How do thiazide-like diuretics work?
Inhibits Na+/Cl- in distal convoluted tubule
This causes a reduction in circulating volume and causes vasodilation
Are thiazide-like diuretics effective in moderate renal imparement?
No, but if used eGFR should be measured before and during the use of thiazide diuretics (plasma potassium levels should also be measured)
What are some important side effects associated with thiazide-like diuretics?
Hypokalaemia (less excitable tissues)
Postural hypotension
Impaired glucose control
Do not use in gout
What is the second line of treatment for hypertension?
Thiazide-like diuretics
What is the first line of treatment of hypertension?
ACEIs and AT1 receptors
What is the last choice of treatment of hypertension?
Alpha-blockers
Name an alpha blocker
Doxazosin, prazosin
How do alpha-blockers work and why are they the last choice treatment for hypertension?
They are competitive receptor antagonists of alpha 1 adrenoceptors
The last choice as they have a widespread of side effects, which make them poorly tolerated
Name a beta-blocker
Atenolol, propranolol
Why are beta-blockers no longer recommended as first-line treatment for hypertension?
They have reduced effectiveness at preventing stroke and increased risk of diabetes
Why are patients with asthma and COPD advised to not use beta-blockers?
Beta-blockers are not only selective to beta1 receptors but b2 receptors which are located in the lungs. This can cause bronco constriction, worsening asthma, and COPD.
When should patients be given beta-blockers?
in patients with angina or past MI
childbearing
Increased sympathetic drive
Intolerance to ACEIs / ATRA
