Table 1.

Risks, diagnosis, prevention, and treatment of acyclovir crystal nephropathy.

Risk factors	Laboratory and clinical findings	Prevention	Treatment
Hypovolemia	Increased Cr, rapid and usually within 12–48 hours	Establish euvolemia before medication administration	If possible, discontinue or reduce dose
Rapid IV infusion	Pyuria	Infuse drug slowly (over 1-2 hours)	Establish high urinary flow with IV fluids and furosemide (>150 cc/hr)
Concurrent acute kidney injury before medication administration	Hematuria	Adjust dose for renal function	Hemodialysis if necessary
Excess medication dosage in relation to renal function	Birefringent Needle-shaped crystals	Avoid other nephrotoxic agents	May replace acyclovir with famciclovir in certain instances while increasing urinary flow rate
Concurrent use of other nephrotoxic agents	Pt. may complain of associated flank pain
	Pt. may be oliguric

IV: intravenous, Cr: Creatinine, cc: milliliters, and hr: hour