Which is the most common cause of medication-induced acute kidney injury?

Which is the most common cause of medication-induced acute kidney injury?

• A. Amphotericin B
• B. Aminoglycosides
• C. NSAIDs
• D. ACE inhibitors

Answer: (B)

The main idea is that medication-induced kidney injury most often comes from drugs that directly injure the kidney’s tubules, with aminoglycosides being the classic and most common offender. These antibiotics are filtered by the kidneys and taken up by proximal tubular cells, where they accumulate in lysosomes and mitochondria. This buildup causes cellular injury, disrupts normal tubular function, and can lead to acute tubular necrosis. It’s typically dose-related and tends to appear after several days of therapy, especially in patients who are older, dehydrated, have preexisting kidney dysfunction, or are receiving other nephrotoxic insults. Because the damage is tied to tubular toxicity from the drug and tends to improve after stopping the medication, recognizing the pattern early and discontinuing the offending agent usually leads to recovery, though it can take time and may leave some residual impairment if exposure was prolonged. Amphotericin B is also nephrotoxic and can cause AKI, but it is not as common a cause as aminoglycosides in many clinical settings. NSAIDs can precipitate AKI by reducing renal perfusion through afferent arteriolar constriction and can cause interstitial nephritis, while ACE inhibitors can lead to AKI mainly in cases of reduced renal perfusion such as bilateral renal artery stenosis or dehydration. These mechanisms are important but, in aggregate, occur less frequently than aminoglycoside-induced tubular injury.

The main idea is that medication-induced kidney injury most often comes from drugs that directly injure the kidney’s tubules, with aminoglycosides being the classic and most common offender. These antibiotics are filtered by the kidneys and taken up by proximal tubular cells, where they accumulate in lysosomes and mitochondria. This buildup causes cellular injury, disrupts normal tubular function, and can lead to acute tubular necrosis. It’s typically dose-related and tends to appear after several days of therapy, especially in patients who are older, dehydrated, have preexisting kidney dysfunction, or are receiving other nephrotoxic insults.

Because the damage is tied to tubular toxicity from the drug and tends to improve after stopping the medication, recognizing the pattern early and discontinuing the offending agent usually leads to recovery, though it can take time and may leave some residual impairment if exposure was prolonged.

Amphotericin B is also nephrotoxic and can cause AKI, but it is not as common a cause as aminoglycosides in many clinical settings. NSAIDs can precipitate AKI by reducing renal perfusion through afferent arteriolar constriction and can cause interstitial nephritis, while ACE inhibitors can lead to AKI mainly in cases of reduced renal perfusion such as bilateral renal artery stenosis or dehydration. These mechanisms are important but, in aggregate, occur less frequently than aminoglycoside-induced tubular injury.