A Unique Case of Valacyclovir Toxicity and Pseudobulbar Affect in a Patient On Peritoneal Dialysis

Abstract

There are a few cases of valacyclovir-associated neurotoxicity (VAN) reported. This case report documents a case of a 55-year-old male presenting with emotional lability or pseudobulbar affect as the predominant or sole manifestation of VAN. A failure to adjust valacyclovir's dose for herpes simplex infection in the setting of dialysis-dependent end-stage renal disease (ESRD) preceded VAN in this patient. The patient presented with involuntary and uncontrollable outbursts of emotion. Computerized tomography (CT) scan identified no underlying cause. A complete neurological examination with cognitive assessment was performed, with no abnormalities. He benefited from the use of aggressive peritoneal dialysis (PD) that was employed to enhance valacyclovir's clearance in this case of intractable VAN. On discharge, the patient was back to baseline mental function.Traumatic brain injury, neoplasm, vascular lesions, metabolic abnormality, neurological disease, herpetic encephalitis, and disorders of mood were ruled out. This led to the hypothesis of encephalopathy due to valacyclovir intoxication. Given that the clinical manifestations were related to ESRD, a dose-adjustment of valacyclovir is imperative in the setting of ESRD to prevent VAN. Our case presents important clinical variations. Firstly, our patient demonstrates that VAN may present with no focal neurological impairment, but pseudobulbar affect. Secondly, aggressive PD was useful in this case for the treatment of VAN as opposed to hemodialysis. We believe that it cleared valacyclovir resulting in the resolution of symptoms.

Neurotoxicity Secondary to Valacyclovir

“…Peritoneal dialysis (PD) is traditionally not preferred for enhancing valacyclovir elimination, but in case studies it has been shown to be useful in expediting drug elimination in ESRD with baseline PD. 4 Based upon the temporal relationship of valacyclovir dosing and the occurrence of neurotoxicity in this patient, the calculated Naranjo et al 5 adverse drug reaction probability scale score was 4, suggesting valacyclovir as a possible cause. Based upon the clinical assessment and input from the family, the patient returned to baseline mental status after the first secession of HD.…”

“…Peritoneal dialysis (PD) is traditionally not preferred for enhancing valacyclovir elimination, but in case studies it has been shown to be useful in expediting drug elimination in ESRD with baseline PD. 4…”

A Case Report of Valacyclovir-Associated Neurotoxicity in End-Stage Renal Disease: A Rare but Preventable Side Effect

“…In one case, a 77-year-old ESRD patient presented with confusion and hallucination after ingesting a high dose of valacyclovir 3 grams per day for shingles [ 6 ]. Another case presented an ESRD patient taking a higher dose of 4 grams per day presenting with pseudobulbar affect [ 7 ]. In addition to mild to moderate neurotoxicity, valacyclovir also manifests as severe altered mental status and seizures.…”