CPRS 45: Diuretics and ACE Inibitors Flashcards
Consider Loop diuretics:
- Where is the site of action
- What channels does it inhibit
- Name 2 examples
Consider Loop diuretics:
- Where is the site of action: Loop of Henle
- What channels does it inhibit: NKCC Channels
- Name 2 examples: Furosemide, Ethacrynic acid
Consider Loop diuretics Mechanism of Action:
- Inhibits ______ channels
- Reduction in _____ ion and _____ ion absorption from the ascending limb of Loop of Henle to Interstitial fluid
- Less ____ can be reabsorbed from the collecting duct to the interstitial space
- Diuresis
Consider Loop diuretics Mechanism of Action:
- Inhibits NKCC channels
- Reduction in Na+ ion and Cl- ion absorption from the ascending limb of Loop of Henle to Interstitial fluid
- Less H2O can be reabsorbed from the collecting duct to the interstitial space
- Diuresis
Name 2 adverse effects from Loop diruetics
- One about sodium ions
- One about toxic
Name 2 adverse effects from Loop diuretics
- Hyponatremia (Reduced reabsorption of Na+), increased excretion of Na+ in the urine
- Ototoxicity (from ethacrynic acid)
(Hypokalemia, Hypomagnesia)
Consider Thiazide Diuretics
- Site of action?
- Name 2 examples
Mechanism of action
- Inhibit ________ (channel) in distal convoluted tubule at the apical membrane
- Increase the activity of __________ (channel) in the basolateral membrane
- More ____ ion moves from the interstitium to the cell and more _____ ion moves from the cell to the interstitium
- Increased ______ ion reabsorption from the apical membrane
- Name 2 adverse effects
Consider Thiazide Diuretics
- Site of action: Distal convoluted tubule
- Name 2 examples: Hydrochlorothiazide, Chlorthalidone
Mechanism of action
- Inhibit Na/Cl co-transporter (channel) in distal convoluted tubule at the apical membrane
- Increase the activity of Na/Ca exchanger (channel) in the basolateral membrane
- More Na+ ion moves from the interstitium to the cell and more Ca2+ ion moves from the cell to the interstitium
- Increased Ca2+ ion reabsorption from the apical membrane
Name 2 adverse effects:
- Hypercalcemia
- Hyponatremia
Consider Potassium-Sparing Diuretics
- Site of Action?
- Name 2-3 Examples
Mechanism of action:
- Inhibit ___ ion reabsorption from filtrate to cell, Inhibit ___ ion from cell to filtrate
Name 2 adverse effects
- Related to k+
- Related to Metabolic _____
- 1 (selective to Spironolactone)
Consider Potassium-Sparing Diuretics
- Site of Action: Collecting duct
- Name 2-3 Examples: Amiloride, Spironolactone, Eplerenone
Mechanism of action:
- Inhibit Na+ ion reabsorption from filtrate to cell, Inhibit K+ ion from cell to filtrate
Name 2 adverse effects
- Hyperkalemia
- Metabolic Acidosis (Inhibition of H+ excretion)
- Selective to Spironolactone: Impotence
Among the Potassium-Sparing Diuretics
- Amiloride
- Spironolactone
- Eplerenone
Which inhibits Na+ channel activity?
Which ones are antagonists to aldosterone?
Among the Potassium-Sparing Diuretics
- Amiloride
- Spironolactone
- Eplerenone
Which inhibits Na+ channel activity?
Amiloride
Which ones are antagonists to aldosterone?
Spironolactone, Eplerenone
Arrange the efficacy of the 3 types of diuretics
- Loop diuretics
- Thiazide diuretics
- Potassium sparing diuretics
Which 2 shall we choose for the combined therapy?
Arrange the efficacy of the 3 types of diuretics
Loop > Thiazide > Potassium-sparing
Combined therapy: Loop diuretics + Thiazide Diuretics
Consider the RAAS System
Angiotensinogen => Angiotensin I (requires ______)
Angiotensin I => Angiotensin II (requires ______)
Angiotensin II binds to angiotensin receptor
First, Will increased level of angiotensin II lead to vasoconstriction/ vasodilation?
Name 1 Renin Inhibitor
Name 4 ACE Inhibitors
Name 2 Angiotensin Receptor Blockers
Consider the RAAS System
Angiotensinogen => Angiotensin I (requires renin)
Angiotensin I => Angiotensin II (requires ACE)
Angiotensin II binds to angiotensin receptor
First, Will increased level of angiotensin II lead to vasoconstriction/ vasodilation- VASOCONSTRICTION (Please use logic)
Name 1 Renin Inhibitor
- Aliskiren
Name 4 ACE Inhibitors - Captopril - Enalapril - Lisinopril - Quinapril (Carina, Enyu, Joyce Li, Caisa Quinn)
Name 2 Angiotensin Receptor Blockers
- Losartan
- Valsartan
Why does Angiotensin Receptor Blockers have to be used together with Direct Renin Inhibitor
There is a ______________ between Angiotensin II and Renin release, high Angiotensin II level will inhibit Renin
When Angiotensin level reduces
Negative feedback is removed
This will lead to increased ______ production
Which leads to increased production of _______
So the effectiveness is limited without renin inhibitors
Why does Angiotensin Receptor Blockers have to be used together with Direct Renin Inhibitor
There is a negative feedback between Angiotensin II and Renin release, high Angiotensin II level will inhibit Renin
When Angiotensin level reduces,
Negative feedback is removed
This will lead to increased renin production
Which leads to increased production of angiotensin
So the effectiveness is limited without renin inhibitors
Compare ACE receptor inhibitors and Angiotensin receptor blockers.
Which one is better in terms of effect?
Compare ACE receptor inhibitors and Angiotensin receptor blockers.
Which one is better in terms of effect?
- Angiotensin receptor blockers
- More complete blockage of RAAS
- Angiotensinogen => Angiotensin II can happen from ACE-independent pathways
Angiotensin I => Angiotensin II requires ACE
Which another reaction requires ACE as well?
Name a function of Bradykinin
Angiotensin I => Angiotensin II requires ACE
Which another reaction requires ACE as well?
Bradykinin => Inactive metabolite
Bradykinin is for vasodilation
What are the diseases that they intend to treat for using Renin inhibitors, ACE inhibitors and Angiotensin Receptor Blockers?
What are the adverse effects of using these drugs?
Name 3
What are the diseases that they intend to treat for using Renin inhibitors, ACE inhibitors and Angiotensin Receptor Blockers?
- Oedema
- Hypertension
What are the adverse effects of using these drugs?
- Severe hypotension
- Hypokalemia
- Angioedema, dry cough (Selective to ACE inhibitors)
Consider the phenomenon of Aldosterone Escape
There are alternative mechanisms for aldosterone production, besides Angiotensin II => Angiotensin Receptor => Aldosterone
How? Name 2 ways
- ______ (hormone)
- Increased ____ (ion) level
Positive Feedback of Aldosterone
Increased level of aldosterone will lead to increased _______ synthesis, which in turns produce more aldosterone.
Consider the phenomenon of Aldosterone Escape
There are alternative mechanisms for aldosterone production, besides Angiotensin II => Angiotensin Receptor => Aldosterone
How? Name 2 ways
- ACTH
- Increased K+ level
Positive Feedback of Aldosterone
Increased level of aldosterone will lead to increased Angiotensin II synthesis, which in turns produce more aldosterone.
Consider the Loop diuretics and Thiazide Diuretics
Both are used to treat hypertension, which has a longer duration of action, which has a shorter duration of action?
Which type is also used to treat oedema due to retention of salt?
Consider the Loop diuretics and Thiazide Diuretics
Loop diuretics- Short duration of action
Thiazide diuretics- Long duration of action
Which type is also used to treat oedema due to retention of salt- Loop diuretics
