Daily versus alternate-day oral iron in women with iron deficiency anemia: impact of dosing schedule and adherence on hemoglobin recovery.

INTRODUCTION

Iron deficiency anemia (IDA) is common among women of reproductive age and is frequently associated with abnormal uterine bleeding (AUB). Although oral iron is first-line therapy, the optimal dosing schedule remains uncertain. This study compared daily and alternate-day oral iron in real-world practice.

MATERIALS AND

METHODS

We conducted a prospective observational cohort study of women aged 18-70 years with confirmed IDA treated with oral ferrous sulfate at a tertiary referral center between January 2023 and June 2024. Patients received oral iron every 24 h or every 48 h according to physician prescription. AUB etiology was classified using the PALM-COEIN system. Outcomes included hemoglobin change, World Health Organization anemia severity, hemoglobin normalization (≥12 g/dL), adherence, adverse-event-related discontinuation, and intravenous iron escalation.

RESULTS

A total of 171 women were included. Leiomyomas were the most frequent PALM-COEIN category (106 patients, 62.0%). Mean baseline hemoglobin was 9.02 ± 1.45 g/dL. At 6 weeks, mean hemoglobin was 10.91 ± 1.76 g/dL in the 24-h group and 11.26 ± 1.86 g/dL in the 48-h group (p = 0.255). At 3 months, final hemoglobin was available in 147 patients; mean values were 12.79 ± 1.68 g/dL and 12.68 ± 1.62 g/dL, respectively (p = 0.692). Hemoglobin normalization occurred in 75.2 and 71.7% of patients, respectively (p = 0.687). Adherence was high, and discontinuation due to adverse events was uncommon. Intravenous iron escalation was numerically more frequent with alternate-day therapy (26.8% vs. 13.9%; p = 0.056), although escalation decisions were based on clinical judgment without standardized criteria.

CONCLUSION

Both regimens were associated with hematologic improvement. However, because allocation was non-randomized, baseline differences were present, and intravenous iron escalation was not based on standardized criteria, equivalence cannot be inferred. Oral iron dosing should be individualized.