Iron pills side effects
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Side Effects of Iron Pills: A Comprehensive Overview
Iron deficiency anemia (IDA) is a prevalent condition often treated with iron supplements. However, the side effects of these supplements can significantly impact patient compliance and overall treatment effectiveness. This article synthesizes findings from multiple studies to provide a clear understanding of the side effects associated with iron pills and their implications.
Common Gastrointestinal Side Effects of Iron Pills
Nausea, Constipation, and Diarrhea
One of the most frequently reported side effects of iron supplementation, particularly with ferrous sulfate, includes gastrointestinal issues such as nausea, constipation, and diarrhea. These side effects are significant enough to affect patient compliance negatively. For instance, a study comparing ferrous sulfate with an iron-enriched Aspergillus oryzae supplement found that ferrous sulfate caused a higher incidence of nausea, constipation, and diarrhea, although the differences were not statistically significant1. Another systematic review and meta-analysis confirmed that ferrous sulfate significantly increases the risk of gastrointestinal side effects compared to placebo and intravenous iron6.
Vomiting and Abdominal Discomfort
Vomiting is another common side effect, particularly noted in studies involving pregnant women. A study in Bangladesh found that vomiting occurred more frequently in a weekly iron supplementation group compared to a daily regimen, although overall compliance was higher in the weekly group2. Additionally, abdominal discomfort, including symptoms like heartburn and epigastric pain, is often reported, further complicating adherence to iron therapy1 5.
Severe Gastrointestinal Reactions
In rare cases, iron pills can cause severe gastrointestinal reactions, such as iron pill-induced gastritis, which can lead to significant mucosal damage and anemia from gastrointestinal bleeding. This was highlighted in a case study involving a 71-year-old man who developed severe anemia due to iron pill-induced gastritis, necessitating a switch to intravenous iron supplementation8.
Impact on Compliance
Higher Compliance with Lower Side Effects
The side effects of iron pills are a major factor in patient compliance. Studies have shown that formulations with fewer side effects, such as iron-enriched Aspergillus oryzae supplements or heme iron combinations, result in better compliance. For example, compliance was higher with the Aspergillus oryzae supplement compared to ferrous sulfate, likely due to fewer gastrointestinal side effects1. Similarly, a study on blood donors found that a combination of heme and non-heme iron had fewer side effects and better tolerance compared to non-heme iron alone4.
Weekly vs. Daily Supplementation
The frequency of iron supplementation also affects side effects and compliance. Weekly supplementation has been suggested to produce fewer side effects and higher compliance compared to daily regimens. A study comparing daily and weekly iron supplementation in pregnant women found that daily supplementation resulted in higher rates of nausea and constipation, which could reduce compliance5. However, another study indicated that despite a higher frequency of vomiting in the weekly group, overall compliance was still better compared to the daily group2.
Conclusion
Iron supplementation is essential for treating iron deficiency anemia, but the associated gastrointestinal side effects can significantly impact patient compliance. Strategies to mitigate these side effects, such as using alternative formulations with fewer side effects or adjusting the frequency of supplementation, can improve adherence and treatment outcomes. Understanding and addressing these side effects is crucial for the effective management of iron deficiency anemia.
Sources and full results
Most relevant research papers on this topic
Assessment of Gastrointestinal Symptoms and Non-transferrin Bound Iron After Oral Ferrous Sulfate and Iron-enriched Aspergillus Oryzae Supplementation in Women (P24-039-19).
ULT is a safer oral iron supplement for treating iron deficiency anemia with better compliance and less gastrointestinal side effects compared to FeSO4, maintaining normal iron status.
RCT
Very Rigorous JournalDo side-effects reduce compliance to iron supplementation? A study of daily- and weekly-dose regimens in pregnancy.
Weekly iron supplementation in pregnancy had higher compliance compared to daily supplementation, with gastrointestinal side-effects having a limited influence on compliance.
RCT
Rigorous Journal
Highly CitedThe effect of iron tablets' side effects on the level of compliance to consuming iron tablets in pregnant woman: A systematic review
Pregnant women's compliance to iron supplementation decreases due to negative side effects and lack of information from health professionals about iron tablets and their benefits.
Systematic ReviewSide effects of iron supplements in blood donors: superior tolerance of heme iron.
Hemofer, a low-dose iron supplement containing both heme and non-heme iron, has fewer side effects compared to traditional non-heme iron supplements in blood donors.
RCTSide Effects of Daily versus Weekly Iron Supplementation in Pregnant Women
Daily iron supplementation in pregnant women increases the risk of nausea and constipation, potentially reducing compliance.
Ferrous Sulfate Supplementation Causes Significant Gastrointestinal Side-Effects in Adults: A Systematic Review and Meta-Analysis
Ferrous sulfate supplementation significantly increases the risk of gastrointestinal side-effects in adults, but the relationship with dose remains unclear.
Meta-AnalysisRigorous JournalHighly CitedSide Effects of Oral Iron Prophylaxis in Pregnancy – Myth or Reality?
Oral iron prophylaxis in pregnant women, taken between meals, has no significant gastrointestinal side effects.
RCT
Large Human TrialIron pill induced gastritis causing severe anemia
Iron pill gastritis can be life-threatening, leading to severe anemia and gastrointestinal bleeding, and switching to intravenous iron supplementation can improve symptoms.
Case ReportDeterminants of compliance with iron supplementation: supplies, side effects, or psychology?
Poor compliance with iron supplementation is primarily driven by supply availability, not side effects, and can be improved by providing timely reminders, advanced warning, and patient involvement.
Literature ReviewHighly CitedEstimates of total body iron indicate 19 mg and 38 mg oral iron are equivalent for the mitigation of iron deficiency in individuals experiencing repeated phlebotomy
Lower doses of iron, such as 19 mg and 38 mg, are effective for treating iron deficiency anemia in frequent blood donors, suggesting lower doses may be more effective for clinical treatment.
RCTRigorous Journal