1468. Cidofovir Prescribing Patterns and Outcomes in Hospitalized Adults and Children

Abstract

Abstract Background Cidofovir (CDV) dosing is based on limited clinical evidence and varies by indication. The optimal dose to achieve a virologic response has not been established. Routine lab monitoring, renal dose adjustments, and co-administration with intravenous (IV) fluids and probenecid are recommended to limit CDV-associated nephrotoxicity but lack a standard approach. Methods This was a retrospective evaluation of patients admitted to Atrium Health’s Carolinas Medical Center or Levine Children’s Hospital who received at least one dose of CDV from August 1, 2014 through June 30, 2021. The primary objective was to describe CDV prescribing patterns. Secondary objectives included evaluating virologic response, nephrotoxicity, and IV fluid and probenecid use. Results A total of 38 adult and 26 pediatric patients were included and received 44 and 60 CDV doses, respectively. Adult dosing was variable, but the most common regimens for BK virus infections included CDV 0.5 mg/kg every other week for solid organ transplant recipients (Figure 1A-B) and 1 mg/kg weekly for stem cell transplant recipients (Figure 1C). Dosing for adenovirus infections was inconsistent (Figure 1D). All but one of the adult patients evaluated had a decrease in viral load during the first two weeks (Figure 2A-D). In pediatric patients, the most common CDV dose was 1 mg/kg three times weekly which was used in 67% of patients across all indications (Figure 1E-I). Three evaluated pediatric patients had an increase in viral load (Figure 2E-H), but no similarities in dosing or indication were noted. The rate of nephrotoxicity based on pre-defined increases in serum creatinine was 29% for adults and 14% for pediatric patients. Use of IV fluid boluses and probenecid was inconsistent in both adult and pediatric patients (Table 1). Of the patients that did not receive probenecid, only 16.7% of adults and no pediatric patients received a CDV dose > 1 mg/kg. Conclusion Evaluation of virologic response to CDV was limited by small sample size. However, high variability in prescribing patterns highlights the need for standardized, indication-specific dosing. Standardization of IV fluid and probenecid use along with guidance on CDV dose adjustments in patients with renal insufficiency may help decrease the risk of CDV-associated nephrotoxicity. Disclosures All Authors: No reported disclosures.