Intravenous Versus Oral Iron After Gastrointestinal Bleeding: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Background & Objective

Few trials have compared the efficacy of intravenous (IV) iron repletion to oral repletion for patients with gastrointestinal bleeding (GIB). We aim to guide clinical decision-making and optimize treatment strategies through the findings from these studies to provide a step closer to a consensus on the most effective approach to iron supplementation for patients with GIB.

Methods

A systematic review and meta-analysis synthesizing evidence from randomized controlled trials (RCTs) obtained from PubMed, Embase, CENTRAL, Scopus, and Web of Science from inception to April 2024. We used the fixed-effects model to report dichotomous outcomes using risk ratio (RR) and continuous outcomes using mean difference (MD), with a 95% confidence interval (CI). PROSPERO ID: CRD42024542759.

Results

Three RCTs that included 254 patients were included. IV iron was significantly associated with increased complete response (RR: 1.60 with 95% CI [1.24, 2.07], p < 0.01) compared to oral iron, with no significant difference between IV iron and oral iron in partial response (RR: 2.13 with 95% CI [0.60, 7.50], p = 0.24). IV iron was significantly associated with increased Hb concentration (MD: 1.45 g/dL with 95% CI [0.50, 2.40], p < 0.01) and ferritin change (MD: 220.02 μg/L with 95% CI [22.31, 417.73], p = 0.03) compared to oral iron. However, there was no significant difference between IV and oral iron in transferrin saturation (MD: 4.71% with 95% CI [−5.96, 15.38], p = 0.39).

Conclusion

With uncertain evidence, IV iron demonstrated increased hemoglobin and ferritin concentrations and achieved complete response rates in patients with GIB.