How should Mr. W’s IDA be treated?
In our practice, we do not prescribe iron prophylactically, but only if the patient shows evidence of IDA. Instead, we encourage patients to have a diet rich in iron, calcium, and vitamins. It can be useful for patients to work with a nutritionist that can help them select foods that do not exacerbate IBD symptoms but are high in nutrients.
If the patient has active disease that requires iron supplementation due to IDA, we generally do not prescribe oral iron supplements because, in many cases, they can cause stomach upset such as abdominal pain and constipation. Moreover, as mentioned, iron absorption is often impaired in IBD and the patient may not benefit from an oral agent, as is the case with Mr. W. So we prefer to go straight to IV iron infusion.
We do prescribe oral supplementation (usually 100mg/d) if a patient’s hemoglobin is >10 g/dL (mild-to moderate-IDA) and the CRP is normal. However, if the patient shows signs of intolerance or shows no response (hemoglobin <2g/dL increase in 4 weeks) we then go to IV iron therapy.
In patients who have either mild-to-moderate IDA with elevated CRP or clinically active IBD, as is the case with Mr. W, or who have hemoglobin <10 g/dL (severe IDA), we immediately initiate IV iron therapy. The majority of patients I see fall into that category. According to the consensus statement of an International Working Group of experts convened to develop guidelines for gastroenterologists, the preferred route of iron supplementation in IBD is intravenous.3
Indications for IV iron therapy can be found in Table 3.
How should patients be monitored?
It takes time for iron stores to replenish, so we do not recheck the patient’s levels for 2 months after initiation of IV treatment. However, in the case of oral iron supplementation, we check in 4 weeks, which gives us an idea whether or not the patient is responding or not.
Do you have a preferred oral agent?
There are different oral formulations available over the counter for oral iron. All of them have almost equal efficacy. Some patients may tolerate liquid iron better than oral pill form. It is important to remember not to use iron supplements together with antacids or acid reducers. There are also certain antibiotics such as ciprofloxacin that can interfere with the absorption. We prefer recommending that iron be taken with a glass of orange juice, as it is better absorbed in an acidic medium.
Do you have a preferred IV agent?
In most cases, we generally prefer ferric carboxymaltose, which has been studied in patients with iron deficiency of various etiologies, such as chronic kidney disease (CKD), IBD, heavy menstrual bleeding, post-partum IDA, or patients with chronic heart failure and IDA. Importantly, it is specifically indicated for IBD. And it has been shown to be both efficacious and well tolerated.
Additional advantages are that it is extremely convenient, since it is administered in two infusions, administered 1 week apart. Moreover, it can be infused in 15 minutes, which increases the adherence rate. It has also been shown to be more cost effective and convenient than iron sucrose.
Iron sucrose is an older agent indicated for IDA in CKD. It is efficacious, safe, and has good tolerability. But its use is limited due to its increased number of infusions and the length of time—up to 3.5 or 4 hours—of each infusion. Iron dextran, another older agent, takes even longer—up to 6 hours—for infusion and may cause dextran-induced IgE-mediated anaphylaxis, hypotension, and anemia. It also requires test dosing, which is very cumbersome. We prefer to avoid it unless the patient’s insurance does not cover it.
If the patient’s insurance company denies coverage of ferric carboxymaltose and there is a peer-to-peer review option available, we try to do that and advocate for the patient as much as possible. However, we are often forced to follow what the insurance company prefers so as to keep the patient’s costs down.
WHO/UNICEF/UNU. Iron Deficiency Anemia: Assessment, Prevention and Control. Available at: http://www.who.int/nutrition/publications/en/ida_assessment_prevention_control.pdf. Accessed: July 30, 2017.
Kaitha S, Bashir M, Ali T. Iron deficiency anemia in inflammatory bowel disease. World J Gastrointest Pathophysiol. 2015;6(3):62-72.
Gasche C, Berstad A, Befrits R, et al. Guidelines on the diagnosis and management of iron deficiency and anemia in inflammatory bowel diseases. Inflamm Bowel Dis. 2007;13:1545–1553.