Diagnosis and treatment of iron-deficiency anemia in gastrointestinal bleeding: A systematic review

Table 4 Pharmacological characteristics, advantages and disadvantages of worldwide available oral and intravenous iron preparations

Type of preparation	Advantages	Disadvantages
Oral	Safe; readily available (does not require a prescription); administered at home; inexpensive; effective when intestinal absorption is not impaired; no need for venous access and infusion monitoring; eliminates the risk of infusion reactions	Slower repletion of iron stores; Intestinal absorption is relatively low, and may be impaired by concomitant food and medications; gastrointestinal adverse events, including constipation, dyspepsia, bloating, nausea, diarrhoea, heartburn, reducing tolerance and adherence to treatment; compliance difficulted by high pill burden (typically three tablets/day) and gastrointestinal intolerance; diminished efficacy when the uptake is impaired (e.g., in celiac disease, autoimmune gastritis, anemia of chronic disease, or post–gastric or duodenal resection)
Ferric hydroxide polymaltose complex
Sodium ferric gluconate
Ferrous gluconate
Ferrous sulfate
Ferrous fumarate
Intravenous	Fast repletion of iron stores; safe when avoiding preparations with dextran; very effective; gastrointestinal adverse events less frequent; ferric carboxymaltose, iron isomaltoside 1000, and ferumoxytol are considered more stable	Administration by a health care professional, requiring clinic visits; increased costs per dose, but fewer doses required; risk of iron overload and transient increase in oxidative stress; risk of anaphylactic reactions with dextran-containing preparations; risk of hypersensitivity reactions
Ferric gluconate
Iron sucrose
Low molecular weight iron dextran
Ferric carboxymaltose
Iron isomaltoside 1000
Ferumoxytol

Adapted from Muñoz et al[25], Drozd et al[26], Jimenez et al[27], McDonagh et al[28].