Drugs acting on the renin-angiotensin-aldosterone system
"?" in the name is indicative of an ACE inhibitor.
"pril" in the name is indicative of an ACE inhibitor.
"sartan" in the name indicates an Angiotensin receptor blockers (ARBs)
"sartan" in the name indicates an ARB
The effects of angiotensin on blood vessels and the kidney can be inhibited by doing what?
by either preventing the production of angiotensin II or blocking its actions
Do aldosterone antagonists interfere with the effects of angiotensin on blood vessels?
while they prevent the action of angiotensin on the kidney, these drugs don't interfere with its effects on blood vessels
As angiotensinogen circulates around the body, it encounters what in the blood.
As it circulates around the body, it encounters renin in the blood.
Are ACE inhibitors a popular drug for hypertension and are they first-line treatment
on the other hand are a first-line treatment for hypertension and are widely used
WHat type of substance is angiotensinogen
polypeptide
What line of action occurs if some pts experience a sudden drop in renal function when drugs from thsi group are 1st taken?
so renal function is monitored within two weeks of initiating therapy or changing the dose and at regular intervals thereafter. This is done by measuring serum creatinine levels, an increase over 25% prompting discontinuation of the drug
Key effect of angiotensin 2 interaction with angiotensin receptor 1?
vasoconstriction
What happens when renin encounters angiotensinogen?
when it encounters angiotensinogen, it cleaves it into a smaller peptide, known as angiotensin 1
Effects of angiotensin 2 acting on AT1 receptors?
1. release of aldosterone 2. promotes the growth of vascular smooth muscle cells, resulting in hyperplasia and hypertrophy. This narrows blood vessel lumen, increasing resistance to flow
Why do ACE inhibitors cause a dry cough?
ACE breaks down other bioactive peptides like bradykinin and substance P, which are involved in the cough reflex. When ACE is inhibited, the levels of these peptides increase and in some patients it gives rise to a persistent dry cough, which may not be tolerated
ACE inhibitors are the drug of choice for patients of what age and of which ethnicity (or which ethnicity are they never not)
ACE inhibitors are the drug of choice for patients under 55 years of age if they are not of black African or African-Caribbean origin. This group of patients tend to have higher plasma renin activity, so respond better to ACE inhibitors.
ACE inhibitors, angiotensin receptor blockers and renin inhibitors all prevent the actions of what, resulting in what?
ACE inhibitors, angiotensin receptor blockers and renin inhibitors all prevent the actions of angiotensin II, resulting in vasodilation and reduced plasma volume.
Where is ACE found predominantly
ACE is found in several places but is most highly concentrated in the lungs
Role of aldosterone
Aldosterone plays a central role in the homeostatic control of plasma volume and electrolytes. It acts on the nearby kidney to promote the retention of Na+ and H2O, which increases blood volume and consequently cardiac output. That in turn raises flow throughout the circulation and increases blood pressure
Adverse effects caused by inhibition of angiotensin II production or action
All of the drugs that interfere with the reninin-angiotensin-aldosterone system can cause: - hypotension when the first dose is given, especially if administered with a diuretic. The effect usually wears off with time to leave a lower, but not hypotensive, blood pressure - This group of drugs can also cause hyperkalaemia, due to inhibition of aldosterone secretion - Some patients experience a sudden drop in renal function when drugs from this group are first taken,
Angiotensin acts on what in the cortex of the adrenal gland + what does this cause
Angiotensin 2 also acts on AT1 receptors in the cortex of the adrenal gland, where it stimulates release of the steroid hormone, aldosterone
WHat is one of the msot potent natural vasoconstrictors
Angiotensin 2 is one of the most potent natural vasoconstrictors
What will angiotensin interact with?
Angiotensin 2 then interacts with the angiotensin receptor 1, or AT1 receptor and that results in several effects
As angiotensin 1 circulates through the lungs it is exposed to what?
Another enzyme, angiotensin converting enzyme, known generally as ACE
What does ACE do?
It cleaves angiotensin 1 further to angiotensin 2
How angiotensin 2 causes vasoconstriction?
It directly contracts vascular smooth muscle via AT1 receptors on the muscle, but it also acts on AT1 receptors located on the sympathetic nerve endings. Stimulating these receptors promotes noradrenaline release, which amplifies the vasoconstrictor effect.
Role of renin inhibitors or ACE inhibitors (act the same way)
Production of angiotensin II is prevented and it can be prevented by inhibiting the conversion of angiotensinogen to angiotensin I by renin, or by blocking the conversion of angiotensin I to angiotensin II by ACE.
Role of angiotensin receptor blockers
The actions of angiotensin II are prevented by drugs that compete with angiotensin for binding to the AT1 receptor
Are renin inhibitors new or old drugs and are they are standard treatment for hypertension?
Renin inhibitors are a relatively new group of drugs and are not yet a standard treatment for hypertension
When are Angiotensin receptor blockers (ARBs) used and are they as effective as ACE at lowering blood pressure?
These drugs are as effective as ACE inhibitors at lowering blood pressure and are used when ACE inhibitors are not tolerated.
Why are the specific pts that are given ACE inhibitors better at responding to ACE inhibitors?
This group of patients tend to have higher plasma renin activity, so respond better to ACE inhibitors
What is renin?
a hormone & enzyme
How to avoid persistent dry cough as a side-effect of ACE inhibitors?
an angiotensin receptor blocker van be prescribed instead as it blocks events downstream of ACE, so avoids its interaction with other peptides
Why should pts with renal stenosis not be given any drug that interferes with angiotensin production or action?
because it can cause the development severe and progressive renal failure as a result.
effect of angiotensin on the kidney can be inhibited by what?
effect of angiotensin on the kidney can be inhibited by aldosterone antagonist
Where is angiotensinogen made
in the liver
Where is renin made
kidneys
