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

Abstract

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, -0.3%; 95% CI, -0.5% to 0.0%) and infection-related hospitalization (risk difference, -1.5%; 95% CI, -2.3% to -0.6%). 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.

Keywords: Anemia; cardiovascular events; chronic kidney disease (CKD); end-stage renal disease (ESRD); hemodialysis (HD); hospitalization; infection; intravenous iron formulations; iron sucrose; mortality; safety; sodium ferric gluconate.