Diuretics

Question 1

how are diuretics classified?

Answer 1

Site of action

mechanism of action

Question 2

What are the types of diuretics?

Answer 2

Thiazides
Loop
Osmotic
Aldosterone Antagonists
Carbonic Anhydrase Inhibitors
K+ Sparing

Question 3

What is the mechanism of action and site of action of thiazide diuretics?

Answer 3

Mechanism of Action
Inhibit Na and Cl reabsorbtion
Site of Action	Ascending loops of Henle
What really happens?
↑ excretion of ions
↓ K+ 
↓ extracellular fluid volume

Question 4

What are the clinical uses of thiazides?

Answer 4

Essential HTN (alone or in combo)
Edema
Diabetes Insipidus**
Hypercalcemia**

Question 5

how do thiazides exert their antihypertensive effect?

Answer 5

Initially, ↓ extracellular fluid volume
↓ cardiac output
Long term, peripheral vasodilation

Question 6

What are the side effects of thiazides?

Answer 6

HYPOKALEMIC, HYPOCHLOREMIC METABOLIC ALKALOSIS
Cardiac Dysrhythmias
Hypokalemia
Hypovolemia
Orthostatic hypotension
Hyperglycemia
Hyperuricemia
Renal/hepatic failure

Question 7

What are 2 examples of loop diuretics?

Answer 7

Ethacrynic acid

Furosemide

Question 8

How do loop diuretics work?

Answer 8

Inhibit ion reabsorption in the medullary portion of ascending limbs of loop of Henle

Question 9

What are clinical uses of loop diuretics?

Answer 9

Mobilization of edema

Treatment of ICP

Differential diagnosis of oliguria
-pt must be normal volemic and good kidneys before you give it
NOT treatment for essential HTN

Question 10

What are the side effects of loop diuretics?

Answer 10

Fluid and electrolyte imbalance
-Hypokalemic metabolic alkalosis
Hypokalemia
↑ Digitalis toxicity
Potentiate NMB drugs
Hyperuricemia
Aminoglycoside toxicity
Sulfonamide allergy

Question 11

What are some characteristics and MOA of osmotic diuretics?

Answer 11

Freely filterable at the glomerulus
Undergo limited reabsorption
Resist metabolism
Pharmacologically inert
Mechanism of Action
↑ osmolarity of renal tubular fluid and prevents reabsorption of water
↑ plasma osmolarity

Question 12

What are clinical uses for osmotic diuretics?

Answer 12

Prophylaxis against renal failure
-before cross clamp if clamped above renal artery
Differential Diagnosis of oliguria

Treatment of Increased ICP

Reduction of Intraocular pressure

Question 13

What are the side effects of osmotic diuretics?

Answer 13

Pulmonary edema
Hypovolemia
Electrolyte imbalanc
Plasma hyperosmolarity

Question 14

What is the dose for mannitol?

Answer 14

0.25-1 g/kg

Question 15

What are examples of K sparing diuretics?

Answer 15

Tiamterene

Amiloride

Question 16

Where do k sparing diuretics work?

Answer 16

convoluted tubules

Question 17

What are the clinical uses of K sparing diuretics?

Answer 17

used in place of or in combo with other diuretics

Question 18

What is the side effect of K sparing diuretics?

Answer 18

hyperkalemia

Question 19

What is an example of an aldosterone agonist?

Answer 19

spironolactone

Question 20

What is the use of aldosterone antagonists?

Answer 20

usually only hepatic failure/ascites

Question 21

What is an example of carbonic anhydrase inhibitor? What does it do?

Answer 21

acetazolamide

inhibits CA in proximal tubules/inhibits naHCO3 reabsorbtion

Question 22

What are the clinical uses of carbonic anhydrase inhibitors?

Answer 22

Eye surgery-decrease production of vitreous humor-> decrease IOP

Question 23

What is the onset time and dose of Lasix?

Answer 23

Onset: 2-10 min
Dose: 0.1 - 1 mg/kg

Question 24

How much Lasix is needed to increase urine output?

Answer 24

Only 10 mg or 1cc

Question 25

What is usually given to treat hyperkalemia during liver transplant?

Answer 25

Lasix

Question 26

What diuretic is not good for heart failure patients?

Answer 26

Mannitol since it acutely increases intravascular volume

Question 27

What electrolyte imbalances do osmotic diuretics cause?

Answer 27

Hyperkalemia
Hypernatremia

Think of “free water”

Question 28

Lasix is associated with ________ alllergy

Answer 28

sulfa