Abstract
OBJECTIVE: Data comparing clinical outcomes of different intravenous iron products is limited. The purpose of this study was to compare the efficacy and safety of iron sucrose (IS) and ferric carboxymaltose (FCM) on hemoglobin levels. METHODS: This retrospective study was conducted at our quaternary care hospital between May 2015 and June 2019. Adults who received either of the study drugs were included in the analysis. Only the first encounter was used for patients who received multiple iron courses. Wilcoxon signed-rank test was used to compare outcomes versus baseline medians in each group separately, while Mann-Whitney U test was used to compare the change between baseline and outcome medians between both groups. RESULTS: A total of 643 patients were included in the analysis, with 311 receiving iron sucrose (IS) and 332 receiving ferric carboxymaltose (FCM). The median Charlson Comorbidity Index (CCI) was 1 (0-5) for IS and 4 (0-7) for FCM (P < .001). Both iron products significantly increased hemoglobin levels by the end of the study compared to baseline, from 93 (84-105) to 114 (99-127) g/L (P < .001) in the IS group and from 92 (81-103) to 103 (87-117) g/L (P < .001) in the FCM group. Additionally, the change in hemoglobin was significantly more pronounced with IS 16.5 (5-29) g/L versus 6.5 (-1 to 21) g/L for FCM (P < .001). Stepwise multivariable linear regression analysis revealed that baseline hemoglobin [β = 0.52 (0.4-0.6); P < .001], erythrocyte stimulating agents use [β = -7.4 (-11 to -3.8); P < .001], total iron product dose [β = 0.01 (0.01-0.02); P < .001], blood transfusion [β = -9.5 (-12 to -6.6); P < .001], CCI [β = -0.6 (-1 to -0.12); P = .013], and FCM [β = -9.5 (-12 to -6.6); P < .001] were the main predictors of hemoglobin level at the end of the study. CONCLUSION: Multiple factors were shown to affect hemoglobin levels, which need to be considered when managing anemia, including the type of iron formulation used. Our findings need to be verified in larger prospective studies.