Comparative Short-term Safety of Sodium Ferric Gluconate Versus Iron Sucrose in Hemodialysis Patients

Background: Despite different pharmacologic properties, little is known about the comparative safety of sodium ferric gluconate versus iron sucrose in hemodialysis patients. Study Design: Retrospective cohort study using the clinical database of a large dialysis provider (2004-2005) merged with administrative data from the US Renal Data System. Setting & Participants: 66,207 patients with Medicare coverage who received center-based hemodialysis. Predictors: Iron formulation use assessed during repeated 1-month exposure periods (n = 278,357). Outcomes: All-cause mortality, infection-related hospitalizations and mortality, and cardiovascular-related hospitalizations and mortality occurring during a 3-month follow-up period. Measurements: For all outcomes, we estimated 90-day risk differences between the formulations using propensity score weighting of Kaplan-Meier functions, which controlled for a wide range of demographic, clinical, and laboratory variables. Risk differences were also estimated within various clinically important subgroups. Results: Ferric gluconate was administered in 11.4%; iron sucrose, in 48.9%; and no iron in 39.7% of the periods. Risks for most study outcomes did not differ between ferric gluconate and iron sucrose; however, among patients with a hemodialysis catheter, use of ferric gluconate was associated with a slightly decreased risk for both infection-related death (risk difference, 20.3%; 95% CI, 20.5% to 0.0%) and infection-related hospitalization (risk difference, 21.5%; 95% CI, 22.3% to 20.6%). Bolus dosing was associated with an increase in infection-related events among both ferric gluconate and iron sucrose users. Limitations: Residual confounding and outcome measurement error. Conclusions: Overall, the 2 iron formulations studied exhibited similar safety profiles; however, ferric gluconate was associated with a slightly decreased risk for infection-related outcomes compared to iron sucrose among patients with a hemodialysis catheter. These associations should be explored further using other data or study designs. (C) 2016 by the National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.