Acyclovir-associated encephalopathy triggered by nonsteroidal anti-inflammatory drugs

Hiroki TAKAHASHI; Yasufumi TAKAHASHI; Takehiro HIRAYAMA; Yui KAMIJO; Naoki EZAWA; Teppei FURUKAWA; Rikiya FURUTANI

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Acyclovir-associated encephalopathy triggered by nonsteroidal anti-inflammatory drugs

VernacularTitle:Acyclovir-associated encephalopathy triggered by nonsteroidal anti-inflammatory drugs
Author: Hiroki TAKAHASHI ¹ ; Yasufumi TAKAHASHI ² ; Takehiro HIRAYAMA ³ ; Yui KAMIJO ¹ ; Naoki EZAWA ¹ ; Teppei FURUKAWA ² ; Rikiya FURUTANI ¹
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1. Neurology, National Hospital Organization Shinshu Ueda Medical Center, Japan
2. Nephrology, National Hospital Organization Shinshu Ueda Medical Center, Japan
3. Pharmacy, National Hospital Organization Shinshu Ueda Medical Center, Japan
Keywords: acyclovir-associated encephalopathy; drug-induced encephalopathy; non-steroidal anti-inflammatory drugs
From:Journal of Rural Medicine 2025;20(2):147-149
CountryJapan
Language:en
Abstract: Objective: Both acyclovir (ACV) and valacyclovir (VACV) can cause drug-induced encephalopathy, which occurs primarily in patients with renal impairment because of delayed drug metabolism. Here, we report a case of ACV-associated encephalopathy precipitated by the addition of nonsteroidal anti-inflammatory drugs (NSAIDs).Patient: A 97-year-old woman with a 1-d history of altered consciousness was admitted to our hospital. After treatment with ACV and VACV for herpes zoster, NSAIDs were introduced for pain 5 d prior to admission. VACV and NSAIDs were subsequently administered by her primary care physician 3 d before admission.Results: The patient presented with altered consciousness and acute kidney injury, leading to a suspicion of ACV-associated encephalopathy. Her consciousness improved rapidly with hemodialysis. We diagnosed ACV-associated encephalopathy based on a significantly elevated ACV blood level of 32.7 µg/dL.Conclusion: The addition of NSAIDs during ACV or VACV administration may precipitate ACV-associated encephalopathy. When combining ACV or VACV with NSAIDs for the treatment of herpes zoster, careful monitoring of consciousness level and renal function is recommended.