A 45-year-old man with chronic kidney disease secondary to long-standing hypertension presents with fever, dysuria, and flank pain. His baseline eGFR is 25 mL/min and serum creatinine is 2.8 mg/dL. He is started on gentamicin 2 mg/kg IV every 8 hours for a complicated urinary tract infection after urine culture grows gentamicin-sensitive Escherichia coli. His temperature is 38.6°C, blood pressure 148/92 mmHg, and heart rate 98 bpm. On day 3 of therapy, repeat labs show serum creatinine risen to 4.2 mg/dL, urine output has decreased to 400 mL over 24 hours, and urinalysis reveals granular casts and tubular epithelial cell casts. Serum drug levels are noted to be elevated. Which of the following best describes the mechanism of this adverse effect?
- A)Acute interstitial nephritis from drug hypersensitivity
- B)Glomerular filtration barrier disruption by immune complexes
- C)Proximal tubular toxicity from aminoglycoside accumulationGABARITO
- D)Prerenal azotemia from volume depletion
- E)Competitive inhibition of renal filtration by gentamicin
Explicação
Aminoglycosides are nephrotoxic and concentrate in the proximal tubular cells, causing acute tubular necrosis (ATN). The rapid rise in creatinine and presence of urinary casts in a patient with pre-existing renal disease receiving inappropriate dosing is class... Ver explicação completa e trilha adaptativa →