Other diuretic information

Question 1

Common causes of diuretic resistance?

Answer 1

• Incorrect dx –> venoous or lymphatic edema
• Inappropriate NaCl or fluid intake
• Inadequate drug reaching tubule lumen in active form:
• nonadherence
• dose inadequate or too infrequent
• poor absorption (uncompensated HF)
• ↓ RBF (HF, cirrhosis, elderly)
• ↓ functional renal mass (AKI, CKD, elderly)
• proteinuria
• Inadequate renal response
• low GFR (AKI, CKD)
• ↓ effective arterial volume (edematous conditions)
• Activation of RAAS ( edematous conditions)
• nephron adaptation (prolonged diuretic therapy)
• NSAIDs (indomethacin, ASA)

Question 2

Herbal diuretics?

Answer 2

• chicory, dendelion leaves, fennel, etc.
• Some have been shown to cause diuresis, but the active ingredients and MOA are unk
• probably OK by themselves
• should not be miced with other conventional diuretics bc of potential adverse or suboptimal effects

Question 3

How does licorice change your BP?

Answer 3

• Only real licorice
• Containes sweet glycyrrhizic acid, potentiates aldosterone effects in kidney and dose-dependently increases systolic BP (~3-14 mmHg)

Question 4

Diuretic therapy algorithm for renal insufficiency?

Answer 4

• loop diuretic, determine effective dose, and administer as frequently necessary to maintain response –> ADD –> Thiazide according to creatinine clearance: < 20 mL/min = 100-200/day; 20-50mL/min = 20-50 mg/day; > 50 mL/min = 25-50 mg/day –> ADD distal diuretic drug

Question 5

Diuretic therapy algorithm for nephrotic syndrome?

Answer 5

• loop diuretic, determine effective dose, and administer as frequently necessary to maintain response –> ADD –> Thiazide according to creatinine clearance: < 20 mL/min = 100-200/day; 20-50mL/min = 20-50 mg/day; > 50 mL/min = 25-50 mg/day –> ADD distal diuretic drug

Question 6

What is differs with treating cirrhosis or CHF vs RF or nephrotic syndrome?

Answer 6

Consider spironolactone as first line trx with cirrhosis –> HCTZ id creatinine clearance > 50

• Consider HCTZ if creatinine clearance is > 50 as first line of trx before adding a loop diuretic

Question 7

What effect does hyperkalemia have on the heart?

Answer 7

• Tall T waves
• Prolonged PR interval
• Widened QRS interval
• Flattened P waves
• Arrhythmias including bradycardia, v-tach, or fibrillation
• Sinus arrest or nodal rhythm w/ possible asystole

Question 8

What effect does hypokalemia have on the heart?

Answer 8

• Flattened T waves
• ST segment depression
• Prolonged QT interval
• Tall U waves
• Atrial arrhythmias
• V-tach or V-fib

Question 9

Physiological mechanism of edema?

Answer 9

• Hydrostatic pressure pushing fluid out into the interstitium
• Decreased oncotic pressure (decreased proteins) not pushing fluid back into circulation

Question 10

Edema formation is opposed by?

Answer 10

• Increased lymph flow
• Low compliance of interstitial space
• Washout of protein in interstitial space

Question 11

Explain the countercurrent multiplier?

Answer 11

Water, but not sodium is reabsorbed in the descending limb of the loop –> sodium, but not water is reabsorbed at the ascending limb –> forms a concentration gradient in the interstitium