A Comprehensive Monograph on Ferrous Fumarate (DB14491): Chemistry, Pharmacology, and Clinical Application

Executive Summary

Ferrous fumarate is an orally administered iron salt, identified by DrugBank ID DB14491 and CAS Number 141-01-5, that serves as a cornerstone in the management of iron deficiency and iron deficiency anemia. As the iron(II) salt of fumaric acid, its chemical structure, C4​H2​FeO4​, confers one of the highest concentrations of elemental iron among commonly used oral supplements, approximately 33% by weight. This high potency allows for the delivery of therapeutic iron doses in a comparatively smaller physical form, a factor that can enhance patient adherence. Its primary pharmacodynamic effect is the replenishment of systemic iron, an element indispensable for the synthesis of hemoglobin, myoglobin, and numerous metabolic enzymes, thereby restoring oxygen-carrying capacity and cellular function. The pharmacokinetics of ferrous fumarate are governed not by a simple dose-response relationship but by the body's sophisticated homeostatic mechanisms, with intestinal absorption being tightly regulated by iron stores via the hormone hepcidin. Recent evidence has expanded the understanding of its absorption beyond the canonical Divalent Metal Transporter 1 (DMT1) pathway to include clathrin-mediated endocytosis. This complex regulation has profound clinical implications, notably the finding that the acute hepcidin response to an oral dose transiently suppresses subsequent absorption, providing a strong physiological rationale for alternate-day dosing regimens over traditional daily administration. While effective and cost-efficient, the clinical utility of ferrous fumarate is frequently challenged by a high incidence of gastrointestinal adverse effects, including nausea, constipation, and mucosal irritation. Furthermore, its efficacy is subject to a wide array of clinically significant drug-drug and drug-food interactions that can impa