Objectives Educate physicians on the need for monitoring of Aciclivir levels in renal failure.

Design Retrospective case report.

Subjects 59 year old woman presented with acute psychosis following recent herpes zoster treated with oral Aciclovir.

Methods Data collection from; original casenotes, electronic laboratory records, electronic picture archiving and communication system (PACS).

Results Lumbar puncture showed raised protein (0.92 g/L), CSF:serum glucose ratio(0.9), 36 WBCs/cmm(72% polymorphs) and detection of VZV DNA. MRI brain only revealed intracranial-hypotension secondary to lumbar puncture. Despite absence of VZV DNA on surveillance lumbar puncture, she remained minimally responsive. Aciclovir levels were significantly elevated post-dose at 32.7 mg/L (cutoff 10.8 mg/L) and a sedation hold revealed temporal correlation of pre-dose levels (6.4 mg/L) with improvement of GCS, strongly implicating Aciclovir as causative agent. Rapid resolution of encephalopathy occurred upon cessation with no residual neurological compromise.

Conclusions Aciclovir neurotoxicity mimics zoster-related encephalitis and VZV DNA is commonly detected in cerebrospinal fluid of patient’s with herpes zoster (Rudzek et al. 2007). Our case highlights the need for vigilance of Aciclovir-neurotoxicity in renal failure patients.

Reference

1. Rudzek D, Piskunova N, Zampachova E. High variability in viral load in cerebrospinal fluid from patients with herpes simplex and varicella-zoster infections of the central nervous system. Clinical Microbiology and Infection2007;13(12):1217–1219.