Pharmacology: Iberet-Folic 500 is a hematinic containing iron in a sustained-release system, vitamin C for enhancement of iron absorption, and the vitamin B complex including folic acid.
Iron: Iron is required for hemoglobin (Hb) production so that iron deficiency will cause production of smaller red cells, which contain lower level of Hb and can cause microcytic hypochromic anemia.
Vitamin C: Vitamin C supports the body's metabolism and helps absorption of iron from the duodenal level.
Folic Acid: Folic acid is influencing hematopoietic system like vitamin B12 deficiency does.
Pharmacodynamics: Iron, an essential mineral, is a component of hemoglobin and myoglobin and a number of enzymes. The total body content of iron is approximately 50 mg/kg in man and 35 mg/kg in women.
Iron is primarily stored in the body as hemosiderin or ferritin, found in the reticuloendothelial cells of the liver, spleen and bone marrow. Approximately 2/3 of total body iron is in the circulatory red blood cell mass in hemoglobin, the major factor in oxygen transport. Concentration of plasma iron and the total iron-binding capacity of plasma vary greatly in different physiological conditions and disease states.
Approximately 2/3 of folic acid is bound to plasma proteins. Half of the folic acid stored in the body is found in the liver. Folic acid is also concentrated in spinal fluid.
Pharmacokinetics: Absorption: The absorption is increased when iron stores are depleted or red blood cell production is increased. Conversely, high iron blood concentrations decrease absorption. The average dietary intake of iron is 18-20 mg/day. Approximately 10% of this iron is absorbed in healthy individuals and about 20-30% in iron deficient individuals.
Folic acid and iron are absorbed in the proximal small intestine, particularly the duodenum. Folic acid is absorbed maximally and rapidly at this site, and iron is absorbed in a descending gradient from the duodenum distally. After absorption, folic acid is rapidly converted into its metabolically active forms. Except for the folates ingested in liver, yeast and egg yolk, the percentage of absorption of food folates averages about 10%.
The ferrous salt form is absorbed 3 times more readily than the ferric form. The common ferrous salts (sulfate, gluconate, fumarate) are absorbed almost on a milligram-for-milligram basis, but differ in the content of elemental iron. Ferrous sulfate comprises 20% of elemental iron content.
Oral iron is absorbed most efficiently when it is administered between meals. However, conventional iron preparations frequently cause gastric irritation when taken on an empty stomach. Although food can decrease the absorption of iron by 40-66%; gastric intolerance may necessitate administering the drug with food.
Studies with iron in the Gradumet have indicated that relatively little iron is released in the stomach, gastric intolerance is seldom encountered and hematologic response ranks with that obtained from plain ferrous sulfate. Therefore, potential gastric irritation is minimized when iron is administered in the Gradumet form in comparison with conventional oral iron preparations.
Large amounts of ascorbic acid administered orally with ferrous sulfate have been shown to enhance iron absorption. This is apparently due to the ability of ascorbic acid to prevent the oxidation of ferrous iron to the less effectively absorbed ferric form.
The B-complex vitamins are absorbed by an active transport process; they are rapidly eliminated and therefore are not stored in the body. Calcium pantothenate is absorbed readily from the gastrointestinal tract and distributed to all body tissues.
Distribution: Ferrous iron passes through gastrointestinal mucosal cells directly into the blood and is immediately bound to transferrin. Transferrin, a glycoprotein B1-globulin, transports iron to the bone marrow where it is incorporated into the hemoglobin.
Small excesses of iron within the villous epithelial cells are oxidized to the ferric state. Ferric iron combines with the protein apoferritin to yield ferritin and is stored in mucosal cells which are exfoliated at the end of their life span and excreted in the feces.
Elimination: Iron metabolism occurs in a virtually closed system. The majority of iron liberated by destruction of hemoglobin is conserved and reused by the body. The daily excretion of iron from urine, sweat and sloughing of intestinal mucosal cells amounts to approximately 0.5-1 mg in healthy men and 1-2 mg in menstruating women. The half-life of ferrous sulfate is approximately 6 hrs.