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

Abstract

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'. 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. 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 > 26μmol/L in 48h or by ≥ 1.5 times the baseline value. Renal function, haematocrit, and fluid balance were monitored following AKI onset. Data from 10 patients were analysed. Median time to AKI onset was 3.5days (range: 1-6days). Aciclovir was stopped or the dose adjusted. All patients recovered with IV normal saline, aiming for a urine output > 100-150ml/h. The interval between first rise in creatinine and return to normal levels varied between 5 and 19days. 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.