Abstract
A 73-year-old man with multiorgan failure requiring mechanical ventilation and haemodialysis developed herpes labialis infection during his stay in the ICU. This was treated with enteral acyclovir. He developed persistent neurologic impairment soon after acyclovir administration, which, over the course of seven days, progressed to coma, the aetiology of which was unclear. The computed tomograph (CT) of the brain and the cerebrospinal fluid (CSF) examination was normal. The electroencephalogram (EEG) showed generalized slowing. The possibility of acyclovir neurotoxicity was considered and the drug was discontinued. Haemodialysis was instituted and the patient made a complete neurological recovery. We believe that this is the first reported case of coma due to enteral acyclovir.