IV Ferric carboxymaltose and iron sucrose equally effective in anemia of pregnancy: IJOGR

Anaemia is a condition in which the number of red blood cells or their oxygen carrying capacity is insufficient to meet physiologic needs. It is one of the commonest medical disorder among pregnant women in India. Iron deficiency anaemia is accompanied by depleted iron stores and signs of a compromised supply of iron to the tissues. There is physiological variation in haemoglobin levels during pregnancy; at the beginning of a pregnancy, there is a normal reduction in haemoglobin level followed by a slight rise towards the end of pregnancy due to increased haemoconcentration. The initial reduction has been explained to result from increased red cell mass and demands of the fetus which exceeds iron intake with consequent reduction in iron stores of the woman's body.

There are two known factors which play a role in the development of iron deficiency anaemia (IDA) in pregnancy; the first is the woman's iron stores at the beginning of conception and the second is the amount of iron absorbed during gestation.

Anaemia in pregnancy is associated with unfavorable consequences both for the mother and the foetus. The detection of anaemia and its effective management is available, affordable and it is possible to effectively implement these even in the rural setting. Not to mention the fact that these are very cost effective interventions.

There are various promising forms of treatment for iron deficiency anaemia. Oral iron is the most preferred route of administration for mild anaemia. Treatment with iron preparations is used routinely in pregnancy. However, oral iron supplementation often leads to adverse side effects, such as constipation, abdominal pain and other gastrointestinal symptoms. Because of these unwarranted gastrointestinal effects the compliance to iron treatment is highly variable.

Intravenous iron preparations show good potential, especially in cases of severe anaemia. They provide a greater and more rapid iron supply than oral iron therapy without the gastrointestinal side effects of oral preparations and make it possible to avoid blood transfusion which is associated with risks. Iron sucrose has been used for years for i.v. treatment of iron deficiency in pregnant women after the first trimester.

However, its use is limited by the low maximum dosage due to local and systemic side effects in higher doses. In order to avoid these adverse effects the drug has to be administered in multiple infusions of lower doses less than 200 mg per day. Hence it increases the number of days of admission in the hospital and it becomes an extra burden on the hospital resources.

The search for an ideal parentral iron preparation has led to the introduction of ferric carboxymaltose. It comprises a macromolecular iron-hydoxide complex of polynuclear iron hydroxide tightly bound in a carbohydrate shell. This design allows for a controlled delivery of iron within the cells of reticulo-endothelial system and hence subsequent delivery to the iron binding proteins, with a minimal risk of release of large amounts of ionic iron in the serum. This iron preparation can be used intravenously in high doses with up to 1000 mg infused in l5 min with low risk of side effects. Its use is approved in the second and third trimesters of pregnancy.

The aim of this study carried out by Reddy, Kamath and Shettian was to compare i.v. ferric carboxymaltose with i.v. iron sucrose during pregnancy regarding the efficacy and safety profile.

A hospital based randomized prospective study was done from July 2013 to June 2015 in the department of Obstetrics and Gynaecology, A.J. Institute of Medical Sciences, Mangalore. Baseline haemoglobin, peripheral smear and serum ferritin levels were measured to diagnose iron deficiency anaemia. 60 pregnant women who met the inclusion criteria and who formed the study subjects were randomly allocated into two groups comprising of 30 in Group C (Received ferric carboxymaltose) and 30 in Group S (Received iron sucrose). Outcome was assessed by measuring haemoglobin 3 weeks after treatment and a comparison of the safety and efficacy between the two groups was made.

In the present study the post treatment haemoglobin levels in 63.3% of the women in group C compared to 46.7% in group S were found to be 11 or more and mean post treatment haemoglobin levels were comparable in group C and group S (11.016±0.789 vs 10.73±0.821 gm%; p=0.174). Post treatment mean increase in haemoglobin levels was noted between 2.0 to 2.5 gm% in 43.3% of the women in group C compared to 50.0% in group S.

These findings suggest that, both the i.v iron preparations, iron sucrose and ferric carboxymaltose are equally effective in the treatment of iron deficiency anaemia among pregnant women. IV iron sucrose(IS) has been used for many years to treat iron deficiency in pregnant women after the first trimester. However its use is limited by a low maximum dose due to side effects at higher doses. IV ferric carboxymaltose (FCM) can be administered at a higher doses and has a good side-effect profile. Ferric carboxymaltose is approved for use in pregnancy in the second and third trimesters.

The rapid delivery option of a large single dose of ferric carboxymaltose offers a promising treatment modality for pregnant women who need correction of iron deficiency and anaemia over other IV iron formulations that have low dosage limits, such as iron sucrose (200 mg).

This study nevertheless showed that the tolerance of FCM in pregnancy is good and that side effects are rare, even when administered in a much higher dose than IS and it also offers the advantage of requiring less administrations thereby increasing patient comfort. The authors concluded that FCM would seem to be the drug of choice if IV iron treatment is necessary in the second or third trimester of pregnancy.

Although ferric carboxymaltose has a higher cost per treatment than iron sucrose, the greater number of infusions with iron sucrose resulted in a higher overall treatment cost.

Based on the results of this study, it may be concluded that, both the i.v iron preparations are equally effective in treating iron deficiency anemia in pregnancy. This study shows that the tolerance of ferric carboxymaltose in pregnancy is excellent with no side effects, even when administered in a much higher iron dose compared to iron sucrose. However, compared to iron sucrose, ferric carboxymaltose offers the advantage of administration of a much higher iron dosage at a time reducing the need for repeated applications and increasing patients' comfort. Although FCM and IS are almost comparable in terms of cost, the dosage schedule makes it more cumbersome and inconvenient for the patient and reduces the compliance as IS has to be administered in multiple doses.

Source: Reddy, Kamath and Shettian / Indian Journal of Obstetrics and Gynecology Research 2021;8(4):448–453