Concurrent Nephrotoxicity and Neurotoxicity Induced by Oral Valacyclovir in a Patient With Previously Normal Kidney Function

Drug-induced nephrotoxicity and neurotoxicity are commonly encountered problems in clinical practice. We describe a case of concurrent valacyclovir-induced nephrotoxicity and neurotoxicity in a 64-year-old man with no history of renal disease who developed acute renal injury and neurological symptoms after he received two weeks of the standard dose of oral valacyclovir for herpes zoster meningitis. His clinical condition improved significantly after the initiation of hemodialysis. Although nephrotoxicity due to intravenous infusion of valacyclovir and/or acyclovir is not uncommon, oral valacyclovir therapy is rarely associated with nephrotoxicity in patients with no history of renal insufficiency. Additionally, concurrent nephrotoxicity and neurotoxicity due to valacyclovir and/or acyclovir are rarely reported. Clinicians should be aware of these adverse events as immediate recognition and intervention are necessary to prevent morbidity.