Iron deficiency anaemia: How do doctors choose between oral and intravenous iron?

Haemoglobin and iron stores tell you different things

Haemoglobin shows how severe the anaemia is. Ferritin helps assess how much iron the body has in reserve. Inflammation can affect ferritin levels, so the doctor may also look at other results such as transferrin saturation. Even if haemoglobin improves after treatment, the doctor still needs to review your follow-up results to assess iron stores and the cause of the deficiency.[1]

What can get in the way of oral iron treatment?

The body absorbs oral medicines such as ferrous sulfate through the digestive tract. Some people experience nausea or constipation. If oral iron does not have the expected effect, it may be due to how much you actually took, whether you are still losing blood or how well your digestive tract can absorb the iron. The doctor will first work out where the problem lies. A history of persistently heavy periods, surgery on the digestive tract or digestive symptoms alongside the anaemia can all help the doctor investigate the cause.[1]

Intravenous iron bypasses the digestive tract. The doctor may consider it when oral iron is unsuitable. The infusion has to be arranged and monitored because infusion reactions can occur. What needs monitoring varies by product. For example, some patients need to have their blood phosphate checked as directed by their doctor. Replacing iron can improve the deficiency. Any condition causing blood loss or poor absorption still needs to be addressed separately.[1,2]

What to check when continuing care in China

If you took iron by mouth or had an infusion outside China, put the packaging or infusion record together with the blood test results from before and after treatment. Note the date of each test and when you actually took or received the medicine. At your prescribing appointment in China, you can ask, “Is the main issue that I cannot tolerate oral iron, that I am not absorbing it well or that I am still losing iron?” If your doctor suggests an infusion, ask for the generic name, where you will be monitored for adverse reactions, which tests you will need next and which department will review the results. If you do not have the full medicine name, use the medication checklist for a medical visit to China to organise the information you have.[1,2]