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Aciclovir Crystal Nephropathy — ESENeph MCQ

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ModerateAcute Kidney InjuryAciclovir Crystal NephropathyESENeph

A 40-year-old woman develops acute kidney injury with oliguria after receiving IV Aciclovir for herpes encephalitis. Urine microscopy shows birefringent needle-shaped crystals. What is the mechanism of the AKI?

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Correct answer: A — Intratubular crystal deposition and obstruction

IV Aciclovir (and its prodrug Valaciclovir) can cause AKI through intratubular crystal deposition. Aciclovir is relatively insoluble and precipitates as needle-shaped crystals in the renal tubules, particularly when the patient is dehydrated or given rapid boluses. Risk factors include dehydration, rapid IV infusion, high doses, and pre-existing CKD. Prevention involves adequate hydration and slow infusion over 1 hour. Management includes stopping Aciclovir, IV fluids, and the AKI usually recovers.

Reference: KDIGO 2012 – AKI Guideline; Perazella 2019 – Drug-Induced Crystal Nephropathy