A 70-year-old white male with a history of hypertension, hypercholesterolemia, and degenerative joint disease presents to the office because of worsening fatigue, nausea, malaise, and bilateral pedal edema. He also complains of a decreased appetite for the past six weeks. Four weeks ago, he had an upper respiratory tract infection that resolved with over-the-counter medications. He describes his degenerative joint disease as moderately severe, and for which, he has been taking ibuprofen for the past year. His other daily medications for the past six years are metoprolol, hydrochlorothiazide, hydralazine, and simvastatin. He has no known drug allergies. He has a 50-pack-year history of smoking, and occasionally drinks alcohol. His family history is significant for strokes. His labs on this office visit show the following: His urine analysis shows: 4+ protein, 0-1 RBC/HPF, 20-25 WBC/HPF, and a few granular casts. His 24-hour urine protein is 7 g. Ultrasound of the kidneys is unremarkable. His antinuclear antibody titers are 1:40. During his previous visit one year ago, the creatinine was 1.2. Which of the following is the most likely cause of his presentation?

Question

A 70-year-old white male with a history of hypertension, hypercholesterolemia, and degenerative joint disease presents to the office because of worsening fatigue, nausea, malaise, and bilateral pedal edema.  He also complains of a decreased appetite for the past six weeks.  Four weeks ago, he had an upper respiratory tract infection that resolved with over-the-counter medications.  He describes his degenerative joint disease as moderately severe, and for which, he has been taking ibuprofen for the past year.  His other daily medications for the past six years are metoprolol, hydrochlorothiazide, hydralazine, and simvastatin.  He has no known drug allergies.  He has a 50-pack-year history of smoking, and occasionally drinks alcohol.  His family history is significant for strokes.  His labs on this office visit show the following:  His urine analysis shows: 4+ protein, 0-1 RBC/HPF, 20-25 WBC/HPF, and a few granular casts.  His 24-hour urine protein is 7 g.  Ultrasound of the kidneys is unremarkable.  His antinuclear antibody titers are 1:40.  During his previous visit one year ago, the creatinine was 1.2.  Which of the following is the most likely cause of his presentation?

Quizplus · Accepted Answer

Explanation: This patient most likely has analgesic-induced nephropathy. Analgesic-induced nephropathy can present with florid nephrotic range proteinuria. This often results from nonsteroidal antiinflammatory medications which cause a reversible decline in renal blood flow and glomerular filtration rate due to the inhibition of vasodilatory prostaglandin production. NSAIDs can also produce acute interstitial nephritis, wherein a kidney biopsy would show minimal changes and a typical interstitial inflammatory pattern. (Choice A) This patient does not have multiple myeloma. The protein in the urine of multiple myeloma patients is typically composed of light chains which are usually not detected by the dye-reagent strip test used for urine analysis. Serum or urine immunoelectrophoresis, or detection of Bence Jones proteins in the urine, is necessary to make the diagnosis. (Choice B) Even though this patient had a recent upper respiratory tract infection, this does not explain glomerulonephritis. The patient has nephrotic range proteinuria, no RBCs or RBC casts in the urine analysis. (Choice C) Hydralazine can cause drug-induced lupus; however, the drug-induced lupus usually does not cause renal failure. (Choice D) Uncontrolled hypertension can result in chronic renal failure; however, the kidneys are typically small, and the renal failure usually does not result within one year. It usually takes several years with a progressive decline in glomerular filtration rate. Educational Objective: Recognize the manifestations of analgesic-induced nephropathy. Analgesic-induced nephropathy can present with florid nephrotic range proteinuria. Multiple myeloma-induced proteinuria is usually not detected by urine analysis. Drug-induced lupus often does not cause renal failure. Uncontrolled hypertension can cause a progressive decline in glomerular filtration and chronic renal failure, but usually takes several years.

A 70-Year-Old White Male with a History of Hypertension, Hypercholesterolemia