Diuretics in ADHF

Question 1

Loop diuretics use in ADHF

Answer 1

effective at low CrCl (< 30 mL/min)
Administering high-dose intravenous diuretic (2.5 times the previous oral dose) is associated with greater fluid removal.

Question 2

Loop diuretic equivalent doses

Answer 2

furosemide 40 mg PO = furosemide 20 mg IV = bumetanide 1 mg IV or PO = torsemide 20 mg PO = ethacrynic acid 50 mg

Question 3

Thiazides use in AHDF

Answer 3

Weak diuretics when used alone, less effective at low glomerular filtration rate (CrCl < 30 mL/min)
Reserved for add-on therapy when refractory to loop diuretics

Question 4

Loop diuretics in diuretic resistance

Answer 4

Increase dose before increasing frequency of loop diuretic (note ceiling effect at ~160–200 mg of IV furosemide)
Continuous infusion of loop diuretic: Furosemide 0.1 mg/kg/hr IV doubled every 4–8 hr, max 0.4 mg/kg/hr

Question 5

Thiazides doses in diuretic resistance

Answer 5

Hydrochlorothiazide 25–50 mg PO daily, metolazone 2.5–5 mg PO daily (30 min before loop diuretic administration)
Chlorothiazide 250–500 mg IV daily; consider if GI edema; generic is very expensive; reserve for NPO
or refractory to other alternatives

Question 6

Furosemide PK

Answer 6

onset of IV action = 5 min; Avg duration of effect = 6-8hr

Question 7

Bumetanide PK

Answer 7

onset of IV action = 2-3 min; Avg duration of effect = 4-6 hr

Question 8

Torsemide PK

Answer 8

onset of IV action = 10 min; Avg duration of effect = 12-16 hr

Question 9

Ethacrynic Acid PK

Answer 9

onset of IV action = 5 min; Avg duration of effect = 6 hr