Ferrous Fumarate Pharmacokinetics
Iron is mainly absorbed in the duodenum and proximal jejunum in the form of ferrous ions [1]. For non-iron deficiency patients, 5% to 10% of iron intake after oral administration can be absorbed from the intestinal mucosa. With the lack of iron storage in the body, its absorption can increase proportionally. Therefore, for general iron deficiency patients, 20% to 30% of the iron intake can be absorbed. Ingestion of iron with food at the same time reduces its absorption by about 1/3 to 1/2 compared with that of an empty stomach. After being absorbed, iron combines with transferrin and enters the blood circulation. It is used as a raw material for the body to produce red blood cells. It can also be stored in the liver, spleen, bone marrow and other reticuloendothelial tissues in the form of ferritin or hemosiderin. The protein binding rate of this drug is high in hemoglobin, but low in myoglobin, enzymes and iron transporting proteins, and low in ferritin or hemosiderin. Iron is excreted from urine, bile, sweat, shed intestinal mucosal cells and enzymes. The daily excretion is very small, and the total loss is 0.5 to 1.0 mg. Due to menstruation, pregnancy, breastfeeding and other reasons, women excrete an average of about 1.0~1.5mg per day. Those who cannot absorb the drug from the intestine after oral administration will be excreted with feces.
