Match each clinical vignette describing a renal or electrolyte complication of pharmacotherapy with the most likely responsible mechanism or drug effect.
- An inpatient being treated for a severe Pseudomonas aeruginosa bloodstream infection develops a progressive decline in renal function on the eighth day of antimicrobial therapy. The patient remains non-oliguric, but microscopic urinalysis shows an abundance of pigmented, granular casts.Aminoglycoside-induced acute tubular necrosis
- A young adult receiving high-dose intravenous therapy for suspected herpes simplex encephalitis experiences a sudden decrease in urine output 48 hours after admission. Renal function rapidly deteriorates, and urine microscopy shows distinct needle-shaped, birefringent structures.Intratubular precipitation of acyclovir
- An individual managed for bipolar disorder reports excessive thirst and frequent urination of large volumes of pale fluid. Clinical evaluation reveals hypernatremia, and a water deprivation test shows persistently low urine osmolality that does not correct with the administration of exogenous desmopressin.Lithium-induced nephrogenic diabetes insipidus
- An immunocompromised patient on prophylactic therapy for Pneumocystis jirovecii is found to have elevated serum potassium and creatinine levels during a routine check. However, a specialized renal clearance study confirms that the true glomerular filtration rate has remained completely normal.Trimethoprim-induced blockade of distal sodium channels and creatinine secretion
Answer
The correct pairings match the anti-pseudomonal therapy complication to aminoglycoside-induced ATN, the encephalitis treatment complication to intratubular acyclovir precipitation, the bipolar treatment complication to lithium-induced nephrogenic diabetes insipidus, and the pneumonia prophylaxis complication to trimethoprim-induced channel blockade.
Each medication causes a unique and predictable pattern of renal impairment. Aminoglycosides directly damage proximal tubular cells causing ATN. Acyclovir is relatively insoluble in urine and precipitates in the tubules. Lithium impairs aquaporin insertion in the collecting duct. Trimethoprim acts on specific transporters without damaging the glomerulus itself.
Step-by-Step Solution
Key Concept
Recognizing the distinct clinical presentations, timing, and urinary findings of medication-induced nephrotoxicity and electrolyte derangements.
Estimated Time:1m 30s