Possible valacyclovir-related neurotoxicity and aseptic meningitis

Abstract

Objective: To report a case of neurotoxicity and aseptic meningitis in a patient receiving valacyclovir.

Case summary: An 86-year-old white man had started valacyclovir 1 g 3 times a day for a herpetic rash along the left side of his face. He subsequently presented with balance difficulties, constant frontal headaches, and a seizure 1 day prior to admission. Cerebral spinal fluid (CSF) analysis revealed 162 white cells/mm(3), 1 red blood cell/mm(3), glucose 56 mg/dL, and protein 144 mg/dL, with a negative Gram stain. Further laboratory examination failed to demonstrate other causes for the patient's clinical picture. After discontinuation of valacyclovir and supportive care, the patient symptomatically improved.

Discussion: As of the third week of September 2003, only 1 other case of valacyclovir-related aseptic meningitis was published describing a patient with characteristics similar to those of our patient. Our patient's neurologic symptoms may have been due to acyclovir toxicity, but acyclovir-toxic patients present with normal CSF findings. Several drug classes, including nonsteroidal antiinflammatory drugs, antibiotics, and intravenous immunoglobulins, can induce aseptic meningitis. Other reasons for the patient's symptoms or causes of meningitis were excluded, although viral meningitis remains a possibility. Valacyclovir-induced aseptic meningitis was considered to be possible according to the Naranjo probability scale.

Conclusions: Healthcare providers should be aware of valacyclovir as a possible cause of drug-induced aseptic meningitis.