Injectafer for Iron Deficiency Anemia
Dr. Landis, January 2019
Anemia is a decrease in the total amount of red blood cells in the blood. This results in a lowered ability of the blood to carry oxygen. When anemia slowly develops, the symptoms are often vague and may include feeling tired, weak, shortness of breath and decreased exercise capacity. Anemia that develops quickly often has more severe symptoms, which include confusion and increased thirst. For iron deficiency anemia, low iron levels result in symptoms of hair loss, restless legs and Pica. Pica is the diseases in which the afflicted craves non-food items to eat, most commonly ice.
Iron deficiency anemia is a common cause of anemia. This usually occurs from chronic blood loss like increased menstrual bleeding and gastrointestinal loss of blood from diseases like Crohn’s disease and peptic ulcer disease. The iron from the blood loss in the gastrointestinal tract is not all reabsorbed leading to iron deficiency anemia. Rapid blood loss in the gastrointestinal tract results in black, tarry, foul smelling stools.
The most effective treatment for iron deficiency anemia is to stop the source of the blood loss but this is not always possible. There are several treatments including oral iron, IV iron, and blood transfusion. Blood transfusions are rarely done for iron deficiency anemia due to availability, blood compatibility and blood borne diseases.
Oral iron is the first line treatment for iron deficient anemia. Effective dosing is 3 times a day. Vitamin C will help with the absorption of the oral iron. Oral iron is not well tolerated. It can cause constipation and upset stomach. It can be taken with food, but it is not absorbed well when taken with food. Patients end up not taking the iron as directed as it is a medication to be taken 3 times a day and can end up causing constipation and upset stomach.
Starting in 1954, high molecular weight iron infusions were developed for use in iron deficiency anemia. However, there were serious allergic reactions associated with it, so it was not routinely used. In the 1990’s, low molecular weight iron infusions became available. These had a lower number of adverse events. In the early 2000’s, multiple formulations of iron infusions became available that had a lower chance of an allergic reaction.
Injectafer (ferric carboxymaltose) became available in 2013. Injectafer is a 15-minute infusion of 750mg of iron. This is done in 2 sessions over 7 days apart. Injectafer has the advantage of a short infusion time and the low incidence of side effects when compared to other iron infusions. The most frequent side effects were nausea at 7.2% and high blood pressure at 3.8%. Patients saw a return of their hemoglobin level back to normal within 35 days of the initial treatment. This leads to increased energy and increased exercise tolerance. Treatment with Injectafer is quick, effective, and has a low incidence of side effects. It is indicated for patients who could not tolerate oral iron or did not have a good response to oral iron.