Aciclovir-induced acute kidney injury in patients with 'suspected viral encephalitis' encountered on a liaison neurology service

Abstract

Background: Patients with 'suspected viral encephalitis' are frequently empirically treated with intravenous aciclovir. Increasing urea and creatinine are 'common', but rapidly progressive renal failure is reported to be 'very rare'.

Aims: To describe the clinical course and outcome of cases of aciclovir-induced acute kidney injury (AKI) encountered by the Liaison Neurology Service at AMNCH and to highlight the importance of surveillance and urgent treatment of this iatrogenic complication.

Methods: Retrospectively and prospectively collected data from the Liaison Neurology Service at AMNCH on patients who received IV aciclovir for suspected viral encephalitis and developed AKI were analysed. Aciclovir-induced AKI was defined by a consultant nephrologist in all cases as a rise in serum creatinine of > 26 μmol/L in 48 h or by ≥ 1.5 times the baseline value. Renal function, haematocrit, and fluid balance were monitored following AKI onset.

Results: Data from 10 patients were analysed. Median time to AKI onset was 3.5 days (range: 1-6 days). Aciclovir was stopped or the dose adjusted. All patients recovered with IV normal saline, aiming for a urine output > 100-150 ml/h. The interval between first rise in creatinine and return to normal levels varied between 5 and 19 days.

Conclusions: Liaison neurologists and general physicians need to be aware that aciclovir may cause AKI attributed to distal intra-tubular crystal nephropathy. Daily fluid balance and renal function monitoring are essential because AKI may arise even with intensive pre-hydration. Prognosis is good if identified early and actively treated.

Keywords: Aciclovir; Acute kidney injury; Crystal nephropathy; Viral encephalitis.