Pharmacology - Diuretics (Exam 4) Flashcards
Used to reduce abnormal accumulation of excess fluid in the body
Diuretics
Diuretics accelerate the rate of ________ formation
urine
What organ do diuretics act on?
Kidney
What is the mechanism of diuretics?
Reduce Na+ and water reabsorption
Increase water excretion
What are the common uses of diuretics?
- Edema
- Hypertension
- Congestive heart failure
What does the kidney filter?
Large quantities of plasma
The only location in the nephron that is NOT impacted by diuretics (ON EXAM)
Glomerulus
What is responsible for water reabsorption by the collecting duct?
Medullary osmotic gradient
What are the 5 main classes of diuretics and their sites of action within the nephron?
- Carbonic anhydrase inhibitors - PCT and PST
- Osmotic diuretics - PCT, PST, thin descending and ascending limb
- Loop diuretics - thick ascending limb
- Thiazide diuretics - DCT
- K+ sparing diuretics - CCT
As you move away from the proximal tubule, diuretics are _________ (more/less) effective
less
Where is the primary site of action for carbonic anhydrase (CA) inhibitors? (ON EXAM)
Proximal tubule
What does carbonic anhydrase do?
Transports HCO3- across membranes
What are CA inhibitors used for? (ON EXAM)
Glaucoma
Acute mountain sickness
What is the suffix for CA inhibitors?
“-amide”
What 3 things do CA inhibitors cause? (ON EXAM)
- Hyperchloremic metabolic acidosis
- Hypokalemia
- Stones
What are the side effects of CA inhibitors? (ON EXAM)
Hyperchloremic metabolic acidosis
Renal stones
Renal K+ wasting
What drug is an osmotic diuretic?
Mannitol (Osmitrol)
Only class of drugs that causes acidosis AND hypokalemia (ON EXAM)
CA inhibitors
What part of the nephron do osmotic diuretics act on?
Proximal tubule
Thin descending and ascending limbs
What is the mechanism of osmotic diuretics?
Produces an osmotic gradient by pulling water into the lumen
Prevents reabsorption of water and solute
Osmotic diuretics are freely filtered by the ________
glomerulus
T/F osmotic diuretics have limited reabsorption and are relatively inert
True
Osmotic diuretics produce rapid _________
diuresis
Osmotic diuretics decrease ________ _________ and increase _________ _________
blood viscosity; blood flow
Which patients CANNOT use Mannitol (Osmitrol)?
Patients with peripheral edema
Which drug is a loop diuretic?
Furosemide (Lasix)
What part of the nephron do loop diuretics work on?
Thick ascending limb
When you think loop diuretic, you should think…
Lose EVERYTHING
(all ions are lost)
What are the side effects of loop diuretics? (5)
- Hypokalemic metabolic alkalosis
- Ototoxicity
- Hyperuricemia, gout attacks
- Hypomagnesemia
- Allergic rxns
Loop diuretics cause interference with ______ reabsorption
Ca2+