Anemia that develops due to iron deficiency is called iron deficiency anemia. This common condition is treated with iron supplements taken either orally or given through an intravenous (IV) infusion. Ferric carboxymaltose (FCM) is one of the widely used, comparably newer IV iron preparations. Recently, several publications have raised the possibility that FCM may be associated with mild elevations in methemoglobin (metHb), a form of hemoglobin that cannot effectively deliver oxygen to tissues.
Methemoglobinemia is a known, though uncommon, side effect of some drugs. While usually mild and self-limiting, in certain cases it can become clinically significant or even life-threatening. This observational study is being conducted across multiple centers to better understand how often methemoglobinemia occurs after administration of FCM. As part of routine care, venous blood samples will be used to measure metHb levels in patients receiving FCM, and these results will be compared with those from individuals not exposed to the drug.
Who can participate
Age range
18 Years
Sex
ALL
See this in plain English?
AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.
Inclusion criteria
. Adults (≥18 years)
. Presence of anemia (Hb \<12 g/dl in women, \<13 g/dl in men)
. Low ferritin (\<30 mcg/l)
. Patients for whom FCM administration has been decided in routine medical care practice
Exclusion criteria
. Known methemoglobinemia-related diseases (Hb M disease, cytochrome b5 reductase deficiency, etc.)
. Use of drugs associated with methemoglobinemia (acetylsalicylic acid, dapsone, chloroquine, metoclopramide, benzocaine, lidocaine, prilocaine, rasburicase, primaquine, sulfonamide, nitric oxide)
Questions worth asking your doctor
Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.
1Based on my diagnosis and history, is this trial worth exploring for me — or is there a standard treatment we should try first?
2What does this trial's phase tell us about how much is already known about its safety and benefit?
3What would taking part actually involve for me — visits, tests, time, and travel?
4What are the known and possible risks or side effects I should weigh, and how would they be monitored?
5If this trial isn't the right fit, what other options or trials would you suggest I look into?
Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.
Questions for the trial coordinator
The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.
1What does taking part actually involve week to week — how many visits, where, and how long does each one take?
2What costs are covered by the study, and what might I have to pay for myself, including travel, parking, or time off work?
3What happens during screening, and what happens if the study team confirms I don't meet the criteria after those tests?
4Who pays for the scans, blood work, and other tests the trial requires — the study, my insurance, or me?
5How will being in the trial affect my regular care, and will my own doctor stay informed and involved?
6Can I leave the trial at any point if I change my mind, and what would happen to my care if I do?
A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.
What they're measuring
1
Number of Participants with Treatment-Related Clinically Significant Methemoglobinemia
Timeframe: From the time of enrollment through 30 minutes following completion of the infusion. If methemoglobin level is ≥3% after infusion, blood sampling will continue every half hour after the last blood gas for 24 hours until methemoglobinemia is <3%.
. Presence of advanced organ failure (Stage 4 and 5 chronic kidney disease, Child C cirrhosis, NYHA class 3 and 4 chronic heart failure, respiratory failure requiring oxygen supplementation and similar processes)
. Presence of malignancy (with or without cure)
. Presence of active infection (CRP \> 5 mg/dL) and/or other acute disorder/disease