Acyclovir-induced renal failure in the treatment of presumed viral retinitis

Seven university teaching hospitals or retina subspecialty clinics with published experience in the treatment of viral retinitis were surveyed to identify cases of acyclovir-induced nephrotoxicity. Four patients from three university teaching hospitals were identified. These four patients, who were presumed to have viral retinitis and normal renal function, developed acute oliguric renal failure between 48 and 72 hours after the initiation of high-dose (500 mg/m² or 10 mg/kg every eight hours) intravenous acyclovir. Peak serum creatinine concentrations ranged from 3.4 mg/dL to 7 mg/dL. In three of the four patients, renal function returned to normal between four and seven days after discontinuation of the acyclovir. Reduced dosage of either intravenous or oral acyclovir was not associated with recrudescence of the acute renal failure in any of these three patients. The authors' findings suggest that renal function should be monitored routinely in patients receiving high-dose intravenous acyclovir for the treatment of presumed viral retinitis and that reduction of the acyclovir dose frequently results in resolution of the acute renal failure despite continued treatment of the viral retinitis.