Case 3: Indinavir Nephrotoxicity

Question | Discussion | References | CME Credit

You answered:

	The patient probably had bacterial cystitis caused by an organism resistant to trimethoprim-sulfamethoxazole, and now the infection has evolved into pyelonephritis and should be treated with ciprofloxacin (Cipro).

This answer is incorrect. Crystalluria associated with dysuria or renal colic in the absence of nephrolithiasis occurs in approximately 5-8% of patients treated with indinavir. The crystalluria-dysuria syndrome may be misdiagnosed as infectious cystitis, leading to unnecessary antimicrobial therapy. Urinalysis will reveal crystals with or without leukocytes, and bacterial cultures will be negative.

Choose another answer:

	The absence of stones on the abdominal CT scan rules out nephrolithiasis caused by indinavir.
	The patient likely has indinavir-induced nephrolithiasis and should immediately be referred to urology for lithotripsy.
	The patient likely has indinavir-induced nephrolithiasis and antiretroviral therapy should either temporarily be discontinued or the indinavir plus ritonavir should be changed to another protease inhibitor(s), such as lopinavir-ritonavir (Kaletra). The patient should initially be managed conservatively with hydration and pain control.
	The patient likely has HIV-associated nephropathy causing these acute symptoms.

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