Acute kidney injury and acyclovir-associated encephalopathy after administration of valacyclovir in an elderly person with normal renal function

Abstract

Introduction: Acyclovir (ACV)-associated encephalopathy is related to an increase in plasma levels of 9-carboxymethoxymethylguanine, an ACV metabolite, and is often reported in patients with renal dysfunction. We report a case of ACV-associated encephalopathy with rapid progression of renal dysfunction after oral administration of valacyclovir (VACV) and review literature of previous ACV-associated encephalopathy cases.Patient concerns: An 88-year-old man was diagnosed with herpes zoster. VACV (3000 mg/day) treatment was initiated. Serum creatinine (Cr) level was 0.80 mg/dL. However, irritability, memory impairment, and decreased responsiveness occurred after 3 days. The Cr level was 6.76 mg/dL on admission.Diagnosis: He was diagnosed with ACV-associated encephalopathy with acute kidney injury.Interventions: VACV was discontinued, hemodialysis was initiated on the day of admission, and then the signs and symptoms improved approximately 72 hours after the admission. Conclusion:Worsening of renal function and encephalopathy should be a focus when using VACV or ACV, regardless of age and original renal function. Acute kidney injury and ACV-associated encephalopathy may particularly occur in the elderly even when renal function is normal. Therefore, regular monitoring of renal function and consciousness is necessary during VACV treatment.

Valacyclovir-associated acute kidney injury

“…Because valacyclovir is rapidly metabolised to acyclovir, it may have similar adverse effects 2. While initially sparse, reports of valacyclovir-associated acute kidney injury are emerging 2–8…”

“…Birefringent, needle-shaped crystals (insoluble acyclovir particles) seen on urinary microscopy support the diagnosis but are not always seen 5. There may be muddy brown casts, indicating acute tubular necrosis 8. Pyuria, albuminuria, hyponatraemia, hyperkalaemia and microscopic haematuria may also be present,2 3 5 although these are non-specific findings.…”

“…Pyuria, albuminuria, hyponatraemia, hyperkalaemia and microscopic haematuria may also be present,2 3 5 although these are non-specific findings. Acute kidney injury with normal urine output has been reported,6 8 as well as oliguria, azotaemia and anuria 3 4 7. Valacyclovir-associated neurotoxicity may be seen in association with acute kidney injury; manifestations include confusion, abnormal movements, stupor and coma 7 8.…”

“…Acute kidney injury with normal urine output has been reported,6 8 as well as oliguria, azotaemia and anuria 3 4 7. Valacyclovir-associated neurotoxicity may be seen in association with acute kidney injury; manifestations include confusion, abnormal movements, stupor and coma 7 8. Response to cessation of valacyclovir is also an important consideration in the diagnosis of valacyclovir-associated acute kidney injury; renal function usually begins to improve within one to two days.…”

“…Valacyclovir is a commonly used antiviral drug for treatment of shingles. While it is usually safe,1 there have been reports of acute kidney injury associated with this drug 2–8. Clinicians should be aware of the potential for acute kidney injury as an adverse reaction to valacyclovir treatment and take steps to prevent it from occurring.…”