Severe acyclovir induced neurotoxicity in an elderly woman with end-stage renal disease and herpes zoster : A case report

Acyclovir (ACV) is a widely utilized antiviral medication for treating herpes simplex virus, cytomegalovirus, and varicella-zoster virus (VZV). Despite its usefulness, ACV can lead to adverse effects like acute renal impairment. ACV is predominantly eliminated through the kidneys, and in cases of renal impairment, there exists a potential for elevated levels, posing a risk of subsequent neurotoxicity. This case highlights the challenges posed by ACV use in patients with compromised renal function. A 64-year-old female presented with unconsciousness persisting for several hours. She had recently self-administered acyclovir (5x800 mg) to manage a herpes zoster outbreak. She had history of Chronic Kidney Disease (CKD) Stage V but refused hemodialysis. She had irregular heart rate of 140-180 beats per minute (with EKG confirming Atrial Fibrillation Rapid Response), a respiratory rate of 26 breaths per minute. Other vital sign was stable. Physical examination identified herpes zoster lesions on the right abdomen. Laboratory results shown blood urea nitrogen of 266 mg/dL, creatinine 13.2 mg/dL, and potassium of 6.9 mmol/L . A month earlier, the level of blood urea nitrogen was 100 mg/dL and creatinine was 7.9 mg/dL, indicating a progressive deterioration in renal function. Given the severity of the patient's condition, hemodialysis was initiated. Over the course of five days, there was a notable improvement in both the patient's clinical condition and level of consciousness.