(517) Characterizing Fluid Hydration Practices Among Patients Receiving Intravenous Acyclovir Therapy

Introduction: Intravenous (IV) acyclovir is known to cause crystal-induced acute kidney injury (AKI). The risk of AKI can be reduced by providing adequate hydration during therapy, but the necessary fluid volume to prevent AKI in this setting remains unclear. Due to this risk, our practice site has implanted an order panel that includes continuous IV isotonic crystalloids when ordering IV acyclovir. The purpose of this study was to evaluate the prevalence of acyclovir-induced AKI and characterize the utilization of IV fluids, with and without the order panel, during IV acyclovir therapy.

Methods: This IRB-approved, retrospective cross-sectional study conducted at an academic medical center included patients ≥ 18 years of age who received ≥ 48 consecutive hours of IV acyclovir. Patients receiving renal replacement therapy or those with AKI prior to acyclovir therapy were excluded. The primary outcome was AKI during or within 48 hours after acyclovir therapy. AKI was defined using the serum creatinine component of the Kidney Disease Improving Global Outcomes criteria due to inconsistent documentation of urine output. Secondary outcomes included total IV fluids received per day, order panel use, and concurrent nephrotoxic agents. Subgroup analysis was done to evaluate prevalence of AKI between patients who received different total volumes of fluid per day, including ≥ 2 L/day or ≥ 1 L/gram of acyclovir/day.

Results: A total of 150 patients were included, among which 32 (21%) had developed AKI. The order panel had a utilization rate of 30% and when utilized, it resulted in significantly more fluids administered per day (1817 mL v. 1267 mL, p=0.005). Patients who developed AKI received less fluid volume per day on average, although this difference was insignificant (1383 mL v. 1580 mL, p=0.962). Use of other nephrotoxic agents did not differ between those with and without AKI. There was no difference in the rate of AKI between patients who received ≥ 2 L/day or ≥ 1 L/gram of acyclovir/day.

Conclusions: Incidence of acyclovir-induced AKI was comparable to what has been reported in the literature. Use of the order panel was associated with greater IV fluid administered, although the ideal volume of fluid required to avoid acyclovir-induced AKI requires further research.