Are any oral iron formulations better tolerated than ferrous sulfate?
– Clinical inquiries: from the family practice inquiries network Todd McDiarmid, E. Diane Johnson EVIDENCE-BASED ANSWER Ferrous salt preparations (ferrous sulfate, ferrous gluconate, and ferrous fumarate) are equally tolerable. (Grade of recommendation: A, based on randomized controlled trial.) Controlled-release iron preparations cause less nausea and epigastric pain than conventional ferrous sulfate (grade of recommendation: A, based on randomized controlled trials), although the discontinuation rates between the 2 iron formulations were similar. Ferrous sulfate remains the standard first-line treatment of iron-deficiency anemia given its general tolerability, effectiveness, and low cost. EVIDENCE SUMMARY A randomized, double-blinded, placebo-controlled study in 1496 subjects examined side-effect rates of 3 iron salt formulations using equal dosages of elemental iron (Table). (1) Gastrointestinal (GI) side-effect rates were not significantly different. The side-effect rate in the fer
