Diuretics & Pharm Treatment of Renal Disorders Flashcards
Drugs for Renal disorders
Sites of action of the different types of Renal Drugs
General function and uses of diuretics?
Function:
- make kidneys excrete more electrolyte thus excretes more water as well
Uses:
- mild to moderate hypertension
- Oedema
What are some examples of Loop Diuretics?
- Furosemide
- Bumetanide
- Torsemide
What do Loop Diuretics do? Where do they act?
- They block 15-25% filtered sodium reabsorption
- Block Na+/K+2Cl- Cotransporter (NKCC2)
- Lead to K+ loss which is unwanted
Place: - Thick Ascending Limb
What are clinical uses of Loop diuretics?
- Oedema
- Liver cirrhosis (permanent scarring that damages your liver and interferes with its functioning)
- renal failure
What are some examples of Thiazides?
- Hydrocholorothiazide
- indapamide
What do thiazides do? What are their Therapeutic uses? AEs?
Function:
- Inhibits NaCl cotransporter
- 5-10% increase of Na+
- K+ loss (unwanted)
Therapeutic uses:
- for mild to moderate HTN
- peripheral Oedema
AEs:
- Hypokalaemia
- Hypovalemia (state of low extracellular fluid volume, generally secondary to combined sodium and water loss)
- Hearing Loss
What are symptoms of Hypokalaemia?
Cardiac:
- Arrhythmias
- increased digoxin toxicity
Neuromuscular:
- muscle weakness
- constipation
Neuro:
- drowsniess
- irritability
- confusion
Why is there Hypokalaemia with Loop diuretics and thiazides?
- they both act upstream -> keep blocking Na+ reabsorp. -> more Na+ at collecting ducts -> therefore Na+ reabsorp at collecting ducts happens at the expense of K+ excretion -> less K+ -> Hypokalaemia
What are the 2 classes of Potassium-sparing Diuretics and examples?
Aldosterone Antagonists:
- Spironolactone
- Eplerenone
- Act at late distal tubule and collecting ducts
Sodium Channel blockers:
- Amiloride
- Act at late distal tubule and collecting ducts
Action of Aldosterone Antagonists
Block aldosterone effets at distal tubule and collecting ducts -> less Na+ reabsorption there -> so K+ doesn’t have to be excreted
Clinical uses of Spironolactone (Aldosterone Antag.)
- used in comb. w thiazide and loop diuretics
- particularly used in conditions associated w Hyperaldosteronism
- add on therapy for resistant HTN
Adverse effects of Spironolactone?
- Hyperkalaemia
- decreased libido
- menstrual disturbances
What is Eplerenone? what does it do?
- Aldosterone receptor antagonist
- blocks actions of aldosterone at late distal tubule and collecting ducts
What is Amiloride and what does it do?
- type of potassium-sparing diuretic
- blocks sodium channels in late distal tubule and collecting ducts
Clinical uses of Amiloride? AEs?
Clin uses:
- blocks Na channels in DCT
- achieves potassium-sparing effect
- used in comb w thiazides and loops
AE:
- Hyperkalaemia
What are osmotic Diuretics? Examples? Action? Uses:
Example:
- Mannitol
MOA:
- acts on whole nephron
- tubular Na+ diluted and Na+ reabsorption rate reduced
- tubular water reabsorption osmotically blocked
Uses:
- for localised oedema
What are Sodium-glucose Cotransporter 2 (SGLT2) Inhibitors? Examples? Action?
Action:
- inhibit effects of SGLT2 in Proximal convoluted tubules
- diuretic properties
Examples:
- Gliflozins
- Dapagliflozin
What is ADH? where is it secreted? what does it do?
AKA vasopressin
Place:
- secreted by posterior pituitary in response to high blood osmolarity
Function:
- Promotes water reabsorption by kidneys -> H2O moves back into blood -> less urine formed
- increased Aquaporins (serve as channels in the transfer of water, and in some cases, small solutes across the membrane)
Pharmacokinetic issues for elderly patients
Elderly patients -> usually impaired kidney functions -> need to lower dosage of drugs
What are drugs that can be toxic if kidney function is impaired?
- Digoxin
- Triple whammy -> RAS inhibitors, NSAIDs, Diuretics
- Metformin (used for type 2 diabetes)
- Aminoglycoside antibiotics -> damage kidneys and hearing
