Drug Induced Nephopathies (DIN)

Question 1

Pseudo-Renal Failure

Answer 1

• Increased production or decreased clearance of renal function markers
• Increased SCr or BUN
• Without actual decrease in kidney function
• Levels return to baseline after drug is stopped
  a) Increased protein catabolism, increasing BUN
  ex. Corticosteroids, tetracycline
  b) Competitively inhibits renal tubule secretion of creatinine, increasing SCr
  ex. Trimethoprim, fenofibrate

Question 2

Hemodynamically Mediated Renal Failure

Answer 2

• Afferent arteriole vasoconstriction
  ex. NSAIDs
• Efferent arteriole vasodilation
  ex. ACEI, ARBs
• Increased SCr and decreased GFR within days of drug initiation

Question 3

ACEI-induced DIN/AKI

Answer 3

• NA and H2O depletion
• Dehydration
• Large drop in systolic BP
• Taking ACEI and NSAID together

Question 4

Glomerulonephritis (GN)

Answer 4

• Immune mediated
• Proteinuria
• Decreased GFR
• Dysmorphic RBCs
  ex. NSAIDs, ampicillin

Question 5

Drug Induced Acute Tubular Necrosis (ATN)

Answer 5

• Dose related
• Granular casts (Muddy brown)
• Epithelial casts
• Increased urinary Na
  ex. Gentamicin, Tobramycin, Amikacin, Contrast dye, amphotericin B
• Increases SCr
• Decreases CrCl
• 5 to 10 days after therapy

Question 6

Risk factors for ATN

Answer 6

• Diabetes
• CKD
• Heart failure
• Dehydration

Question 7

Acute Allergic Interstitial Nephritis (AIN)

Answer 7

• Immune mediated
• Idiosyncratic
• NOT dose related
• Fever, rash
• Eosinophils present
• WBC casts
  ex. Beta-lactams, PPIs
• Corticosteroids may speed up the healing process

Question 8

Chronic Interstitial Nephritis

Answer 8

• Slow progression
  ex. Lithium, cyclosporin, tacrolimus
• May not be cureable

Question 9

Obstructive Nephropathy

Answer 9

• Physical obstruction due to
  a) Crystallization
• lower back/flank pain
• hematuria
  ex. acyclovir, sulfonamides
  b) Tissue degradation
• Oliguria/anuria
• Rhabdomyolysis
• Chemotherapy treatment

Question 10

Obstructive Nephropathy Prevention

Answer 10

• Proper hydration
• Alter urine pH
• Allopurinol, rasburicase (for tumor lysis syndrome)

Question 11

Acute Phosphate Nephropathy

Answer 11

• Calcium phosphate crystal deposition
• Increases SCr
  ex. oral sodium phosphate
• High risk patients; CKD, ACEI, ARB, old diuretics, NSAIDs, Lithium, female, hypertension

Question 12

Example #1 
WBC casts
Leukocyte esterase +4
Turbid pee
Fever
Pain

Answer 12

Diagnosis- Pyelonephritis (sever UTI)

Question 13

Example #2 
Increased hunger, thirst, weight
Polyuria with no dysuria
Glucose +4 
Ketones +4

Answer 13

Diagnosis- Uncontrolled diabetes mellitus