Ferrous sulfate is the most effective, best tolerated, and least expensive preparation. Currently in our country, Ferrous sulfate is available in the form of Retafer, which contains 100 mg/Fe2+. The daily therapeutic dose of iron is 180-200 mg of elemental iron (iron metal). This daily therapeutic dose ensures the highest rate of Hb regeneration (thus, the amount taken is much greater than the amount lost, creating a positive iron balance).
This means that two tablets are needed per day. There are also other Fe preparations which contain less elemental Fe (thus, they irritate the gastrointestinal mucosa less), but in all cases, the daily therapeutic dose of iron of 180-200 mg of elemental Fe must be taken. T ½ is about 6 hours. Iron is better absorbed when taken on an empty stomach, whereas when taken after food or together with it, iron absorption is reduced by 40-50%. However, irritation of the G-I mucosa is common when iron is taken on an empty stomach. The goal of the treatment is not only the rate of Hb increase, but also the well-being of the patient.
Therefore, it is advised for the patient to take the iron preparation in the middle of or after meals, because supporting the treatment is more important than reducing iron absorption. Iron absorption is increased when the preparation is taken in the presence of orange juice or lemon, meat, fish, and is inhibited when taken in the presence of milk, tea, tetracyclines, quinolones, methyldopa, calcium, and cereals. The amount of food also matters. The larger the amount of food eaten, the better the iron preparation will be tolerated. It has also been observed that iron (its salts) are well tolerated when taken by gradually increasing the dose until the full dose of the preparation is reached over a few days.
If gastrointestinal mucosa irritation occurs and when the degree of anemia is mild and/or the cause is removed, iron-deficiency anemia can be treated with a therapeutic dose of iron up to 100 mg/day. In this way, we lower the speed of response to the treatment but increase tolerance to the medication. If the patient does not tolerate Ferrous sulfate, other iron salts can be used: gluconate, fumarate (both compared to the effect of ferrous sulfate), lactate, succinate. Some of them are more expensive than Ferrous sulfate.
Other preparations include:
Using capsules protects teeth from staining, ensures quick passage through the stomach (thus reducing irritation of the stomach mucosa), releases in the intestine, and is absorbed there.
It is preferred that for the treatment of iron-deficiency anemia, iron should not be taken as part of multivitamin-microelement complexes, because the amount of iron they contain does not reach the therapeutic dose of iron and on the other hand, it is released with difficulty from them, reaching the end part of the intestine where it is not absorbed. It is given together with Folic Acid when there is a combined deficit of both elements or for prophylaxis during pregnancy.
To increase (maximize) iron absorption as much as possible, it should be taken before meals, accompanied by Vitamin C, lemon juice, water, etc., and foods and preparations which inhibit its absorption should be taken at least 60 minutes after taking iron or iron should be taken at least 60 minutes after their intake.
Absorption increases when taken together with Vit.C (careful, it increases G-I mucosa irritation, but increases iron absorption up to 7 times), orange juice, meat, fish, succinic acid and is decreased when taken together with cereals, milk, calcium, and tea. In these cases, iron preparations and other preparations (affecting each other's absorption) should be taken at intervals of 2-3 hours.
Oral iron preparations inhibit the absorption of tetracycline in the G-I Tract, but tetracycline also inhibits iron absorption. Tetracycline should be administered 2 hours before and 3 hours after taking oral iron preparations.
Oral iron preparations inhibit the absorption of penicillamine in the G-I Tract. Penicillamine should be administered 2 hours before and 3 hours after taking oral iron preparations.
Chloramphenicol reduces iron absorption and thus will delay the response to treatment with oral iron preparations.
Simultaneous administration of antacids and oral iron preparations will reduce iron absorption.
Avoid taking oral iron preparations 1 hour before or 2 hours after taking antacids.
Simultaneous intake of oral iron preparations and oral quinolones (ciprofloxacin, norfloxacin, ofloxacin) will reduce the absorption of oral quinolones. Quinolones should be administered 2 hours before or 3 hours after taking oral iron preparations.
Simultaneous intake of oral iron preparations and methyldopa and thyroxine (in patients with hypothyroidism) will reduce the absorption of the latter. Methyldopa and thyroxine should be administered 2 hours before and 3 hours after taking oral iron preparations.
Avoid simultaneous intake (but 1 hour before or 2 hours after) of preparations or foods containing calcium (milk, cheese, etc.), tea (tannins).
Iron absorption depends on the level of ferritinemia and is greater in the first days of treatment. Thus, it has been observed that up to day 20 of treatment, iron is absorbed at about 13.5% of the daily dose, while from day 21-30, the amount of iron absorbed drops to 5.1%. Iron preparations reduce the absorption of tetracycline, calcium preparations, cyclosporine, and these have the same effect against iron. A larger amount of food influences the reduction of mucosal irritation.
It is thought that to increase G-I tolerance, the iron preparation should start with a smaller dose and gradually increase until the full dose is reached over a few days. Care must be taken in using iron preparations in the treatment of patients with: stomach ulcer, enteritis, ulcerative colitis, hepatitis, cirrhosis, pancreatitis, hemochromatosis, chronic hemolytic anemia. Prolonged treatment may cause constipation. If there is irritation of the G-I mucosa, remove Vitamin C first, which is used as an adjuvant, but not essential as the iron preparation itself.
Iron is better absorbed when taken on an empty stomach (after eating, absorption decreases by 40-50%). Iron is absorbed when taken before food 10% (also depends on the degree of anemia) and when taken after food is absorbed only 1%. But G-I disorders are more pronounced when taken on an empty stomach. Preferring the reduction of G-I mucosa irritation (thus, the well-being of the patient) over the reduction of iron absorption, it is advised for the patient to take the iron tablets in the middle or immediately after meals.
Fe2+ irritates the G-I mucosa more. Other side effects besides gastric intolerance (nausea, vomiting, pain, or gastric discomfort) are diarrhea, constipation, abdominal pain or discomfort, and in some cases allergic reactions up to anaphylaxis. From the treatment with iron preparations (Retafer and Heferol), many patients complain about increased BP and headaches.
Patients are advised to minimize (minimize) the risk of these effects as much as possible. To facilitate passage through the stomach (or from the stomach to the duodenum) and thus to reduce the potential for esophageal (gastric) irritation, Retafer tablets should be swallowed whole (not kept in the mouth or crushed) with a full glass of water, while the patient stands in an upright or sitting position. The patient should not lie down for 60 minutes after taking the preparation. Capsules and trivalent iron with heme-like complexes can be taken.
Side effects. Allergy from orally taken iron is rare. However, intolerance to orally taken iron is common. The most common side effects are irritation of the G-I mucosa, nausea, vomiting, diarrhea, sometimes constipation, dark-colored feces (careful, dark color of feces comes not only from treatment but also from foods containing iron, upper G-I tract bleeding, swallowed blood from nosebleeds).
To minimize them, some strategies are used:
Treatment with Fe preparations continues for a minimum of three months (6 weeks to eliminate signs and 6 weeks to replenish stores). At least three months, especially when we do not do ferritinemia before and after treatment. Treatment may continue longer if the cause is not eliminated. If iron stores are not replenished, anemia may recur. Replenishment of stores is assessed by the normalization of ferritinemia. Treatment plans for patients with iron-deficiency anemia should include sufficient iron to replenish tissue stores.
If you want to replenish the stores e.g., normal Hb and low ferritin, iron will be given for 6 weeks (1-2 months).
As in the treatment of AF with parenteral iron preparations and with blood transfusions, ferritinemia will not increase (thus, iron reserves at the beginning), but initially AF will be corrected and then iron stores will be replenished. So, with the first doses, there is no way to increase ferritinemia.
Feces will be black to green from Fe. Do not chew the iron preparation tablet as it will cause staining of the teeth.
Capsules give the opportunity for iron not to stay in the mouth, thus to stain the teeth, reduce the irritation of the G-I mucosa, but reduce iron absorption.
For children, Fe solutions are used and doses vary depending on its content and the child's weight. Usually, 1.5-3 mg/kg/day of elemental iron divided into 2-3 intakes is preferred. Still, a gradual increase to the full dose after a few days is preferred again.