Diuretics

Question 1

Carbonic Anhydrase Inhibitors- Examples

Answer 1

Acetazolamide
dorzolamide
methazolamide
dichlorphenamide

Question 2

Carbonic Anhydrase Inhibitors- Mech of Action

Answer 2

inhibit carbonic anhydrase in luminal membrane of PROXIMAL TUBULE, reducing proximal HCO3 reabsorption

Question 3

Carbonic Anhydrase Inhibitors- Main Indications

Answer 3

• reduce intraocular pressure in glaucoma
• lower [HCO3]p in “mountain sickness”
• raise urine pH in cystinuria

Question 4

Carbonic Anhydrase Inhibitors- Other Uses

Answer 4

• hypokalemic periodic paralysis (may require dietary potassium supplements to prevent potassium wasting)
• adjunctive therapy in epilepsy
• solid hypoxic tumors?

Question 5

Carbonic Anhydrase Inhibitors- Side Effects

Answer 5

• metabolic acidosis (due to HCO3 depletion w/ prolonged treatment)
• hypokalemia (acute effect)
• drowsiness
• fatigue
• CNS depression
• paresthesia

Question 6

Osmotic Diuretics (Mannitol)- Mech of Action

Answer 6

• act primarily on the proximal tubule to reduce the reabsorption of water and solutes, including NaCl
• are freely filterable, non-reabsorbable osmotic agents
• ex. MANNITOL, glycerol, urea

Question 7

Osmotic Diuretics (Mannitol)- Main Indications

Answer 7

• treat or prevent Acute Renal Failure (ARF)

Question 8

Osmotic Diuretics (Mannitol)- Other Uses

Answer 8

• reduce intra-cranial or intra-ocular pressure

- enhance urinary excretion of chemical toxins

Question 9

Osmotic Diuretics (Mannitol)- Side Effects

Answer 9

• acute expansion of ECF volume and increased risk of pulmonary edema, hyponatremia (w/ impaired renal function)
• nausea and vomiting
• headache

Question 10

Loop Diuretics- Examples

Answer 10

Furosemide
bumetanide
ttorsemide
ethacrynic acid

Question 11

Loop Diuretics- Mech of Action

Answer 11

• inhibit the Na/K/2Cl cotransport system in the thick ascending limb of Henle’s loop (ALH)

Question 12

Loop Diuretics- Main Indications

Answer 12

• acute pulmonary edema
• hypertension
• congestive heart failure (CHF), in the presence of renal insufficiency or for immediate effect
• ARF, CRF, ascites, and nephrotic syndrome

Question 13

Loop Diuretics- Other Uses

Answer 13

hypercalcEMIA

Question 14

Loop Diuretics- Side Effects

Answer 14

• HYPOVOLEMIA
• hypokalemia
• hypomagnesemia
• hyponatremia
• hyperuricemia (WHICH CAN CAUSE GOUT)
• metabolic alkalosis
• ototoxicity and diarrhea (mainly w/ ethacrynic acid)

Question 15

Thiazide- Examples

Answer 15

chlorothiazide
hydrocholorthiazide
chlorthalidone
metolazone
indapamide

Question 16

Thiazide- Mech of Action

Answer 16

• inhibit NaCl cotransport in early distal convoluted tubule (DCT)

Question 17

Thiazide- Main Indications

Answer 17

• hypertension
• edema due to CHF, hepatic cirrhosis, renal disease
• idiopathic hypercalciURIA (renal calculi)

Question 18

Thiazide- Other Uses

Answer 18

• Nephrogenic Diabetes Insipidus (prevent further urine dilution from taking place in the DCT)

Question 19

Thiazide- Side Effects

Answer 19

Hypokalemia; hyponatremia; hypovolemia;

Hyperuricemia due to enhanced urate reabsorption and hypercalcemia due to enhanced Ca reabsorption

Metabolic alkalosis
Hyperglycemia (insulin resistance); hyperlipidemia.
Hypersensitivity (fever, rash, purpura, anaphylaxis); interstitial nephritis

Question 20

K-Sparing Diuretics- Examples

Answer 20

Spironolactone
eplerenone
amiloride
triamterene

Question 21

K-Sparing Diuretics- Spironolactone & Eplerenone Mech of Action

Answer 21

• competitively block the actions of aldosterone on the collecting tubules

Question 22

K-Sparing Diuretics- Amiloride & Triamterene Mech of Action

Answer 22

• reduce Na entry across the luminal membrane of the principal cells of the collecting tubules

Question 23

K-Sparing Diuretics- Main Indications

Answer 23

• Chronic liver disease: to treat secondary hyper-aldosteronism due to hepatic cirrhosis complicated by ascites (spironolactone, eplerenone)
• to prevent the hypokalemic effects of other diuretics

Question 24

K-Sparing Diuretics- Other Uses

Answer 24

• Primary hyperaldosteronism (Conn’s syndrome; spironolactone, eplerenone)

Question 25

K-Sparing Diuretics- Spironolactone Side Effects

Answer 25

``` HYPERKALEMIA gynecomastia hirsutism menstrual irregularities testicular atrophy (w/ prolonged use) ```

Question 26

K-Sparing Diuretics- Amiloride Side Effects

Answer 26

HYPERKALEMIA | glucose intolerance in diabetic pts.

Question 27

K-Sparing Diuretics- Triamterene Side Effects

Answer 27

HYPERKALEMIA | megaloblastic anemia in pts w/ liver cirrhosis

Question 28

ADH Antagonists- Examples

Answer 28

``` doxycycline lithium tolvaptan conivaptan mozavaptan ```

Question 29

ADH Antagonists- Mech of Action

Answer 29

SIADH | Euvolemic or hypervolemic hyponatremia

Question 30

ADH Antagonists- Other Uses

Answer 30

Congestive Heart Failure (CHF)

Question 31

ADH Antagonists- Lithium, Doxycycline Side Effects

Answer 31

nephrotoxic

Question 32

ADH Antagonists-Tolvaptan, Conivaptan, Mozavaptan Side Effects

Answer 32

``` hypernatremia thirst dry mouth hypotension dizziness ```

Question 33

ACE Inhibitors Interactions

Answer 33

K-sparing diuretics - increased hyperkalemia-->cardiac arrhythmias (monitor serum K closely)

Question 34

Aminoglycosides Interactions

Answer 34

Loop diuretics - ototoxicity and nephrotoxicity (monitor hearing and serum creatinine closely)

Question 35

Anticoagulants Interactions

Answer 35

Thiazide & Loop diuretics - increased anti-coagulant activity w/ loop diuretics; decreased anti-coagulant activity w/ thiazide diuretics

Question 36

B-blockers Interactions

Answer 36

Thiazide & Loop diuretics - hyperglycemia, hyperlipidemia, hyperuricemia - increased plasma levels of propranolol

Question 37

Carbamazepine or Chlorpropamide Interactions

Answer 37

Thiazide diuretics - increased risk of hypnatremia (monitor Na)

Question 38

Digoxin Interactions

Answer 38

Thiazide & Loop diuretics - hypokalemia-->increased digoxin binding & toxicity (monitor K and cardiac function)

Question 39

NSAIDs Interactions

Answer 39

Thiazide & Loop Diuretics K-sparing diuretics - reduced diuretic effect, increased risk of salicylate toxicity w/ high doses of salicylates (thiazide & loop) - increased risk of hyperkalemia w/ K sparing diuretics

Question 40

Quinidine Interactions

Answer 40

Thiazide & Loop diuretics - polymorphic ventricular tachycardia (torsade de pointes)

Question 41

Sulfonylureas Interactions

Answer 41

Loop diuretics - hyperglycemia

Question 42

Steroids Interactions

Answer 42

Thiazide & Loop diuretics - increased risk of hypokalemia (monitor serum K closely)