MethemoglobinemiaNCT06309641
Methemoglobinemia Following Intravenous Iron Treatment
An observational study of Methemoglobinemia and Anemia, run by Claudia Seiler at 1 site in Sweden.
Trial summary
Methemoglobinemia as a side effect of treatment with intravenous iron has not previously been described. This study aims to assess methemoglobin levels in patients with anemia following treatment with intravenous iron, administered as ferric carboxymaltose or ferric derisomaltose. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Methemoglobinemia, Anemia, Iron Deficiencies
- What is being tested?
- Blood sample after treatment and Case reports
- Type of treatment
- Injection or infusion
- How many people
- 50 participants
- Where
- 1 siteSweden
- Study dates
- 2 Sep 2024to 13 Oct 2025
- Phase
- Observational
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Study population: All adults (age ≥ 18 years) with anemia that are scheduled for administration of intravenous iron (ferric carboxymaltose or ferric derisomaltose) in the region of Dalarna, Sweden.
Who may be able to join
- for patients in the cohort study:
- anemia
- prescription of administration of intravenous iron (ferric carboxymaltose or ferric derisomaltose)
- for patients in the case report:
- patients with severe anemia who developed methemoglobinemia following administration of ferric derisomaltose
Who cannot join
- declined consent
- known or suspected methemoglobinemia of genetic or other origin
- previous administration of intravenous iron within one week before study sampling.
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Methemoglobinemia Following Intravenous Iron Treatment Administered as Ferric Carboxymaltose or Ferric Derisomaltose in Patients With Anemia
Methemoglobinemia as a side effect of treatment with intravenous iron has not previously been described. This study aims to assess methemoglobin levels in patients with anemia following treatment with intravenous iron, administered as ferric carboxymaltose or ferric derisomaltose.
Read the detailed description
Methemoglobin is an isoform of hemoglobin without oxygen carrying properties. Higher levels of methemoglobin may impact oxygen transport of the blood and increase the risk of tissue hypoxia. Methemoglobinemia has been reported as side effect of different drugs such as antibiotics or local anesthetics, but not after iron preparations. There is only one case report of increased levels of methemoglobin following intravenous iron therapy.
Patients with anemia due to iron deficiency can be treated with intravenous iron preparations such as ferric carboxymaltose or ferric derisomaltose. Anemia itself reduces oxygen transport of the blood, increasing the risk of tissue hypoxia due to methemoglobinemia in those patients.
This study aims to assess methemoglobinemia following treatment with intravenous iron in patients with anemia. The report will include case reports of patients with severe anemia who developed methemoglobinemia following treatment with ferric derisomaltose. Furthermore, methemoglobin levels are evaluated before and after intravenous iron administration in a cohort of adult patients with anemia who are scheduled to receive ferric carboxymaltose or ferric derisomaltose in routine care.
- Conditions
- Methemoglobinemia, Anemia, Iron Deficiencies, Side Effect
- Being tested
- Blood sample after treatment, Case reports
- Keywords
- Intravenous iron, ferric carboxymaltose, ferric derisomaltose
- Medical subject headings
- Methemoglobinemia, Anemia, Iron Deficiencies
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Blood sample after treatmentDiagnostic test
Blood samples for measurement of methemoglobin are obtained directly before and 30-120 minutes after drug administration.
Case reportsOther
Description of clinical course and methemoglobin levels in patients with severe anemia who developed methemoglobinemia after intravenous administration of ferric derisomaltose.
| Study group | Role | What they receive |
|---|---|---|
| Ferric derisomaltose | Adult patients with anemia scheduled for administration of ferric derisomaltose as prescribed in routine care. Receives: Diagnostic Test: Blood sample after treatment | |
| Ferric carboxymaltose | Adult patients with anemia scheduled for administration of ferric carboxymaltose as prescribed in routine care. Receives: Diagnostic Test: Blood sample after treatment | |
| Case reports | Patients with severe anemia who developed methemoglobinemia after intravenous administration of ferric derisomaltose. Receives: Other: Case reports |
What is being measured
The primary outcome is the main question the study is designed to answer.
Difference in methemoglobin after ferric derisomaltose
Change of methemoglobin (percent) in venous blood after compared to before treatment with ferric derisomaltose.
Measured: 30-120 minutes after start of iron administration
Difference in methemoglobin after ferric carboxymaltose
Change of methemoglobin (percent) in venous blood after compared to before treatment with ferric carboxymaltose.
Measured: 30-120 minutes after start of iron administration
Secondary outcomes (6)
Difference in methemoglobin depending on drug dosage
Change of methemoglobin (percent) in venous blood after compared to before treatment with intravenous iron depending on drug dosage
Measured: 30-120 minutes after start of iron administration
Difference in methemoglobin depending on age
Change of methemoglobin (percent) in venous blood after compared to before treatment with intravenous iron depending on age.
Measured: 30-120 minutes after start of iron administration
Difference in methemoglobin depending on sex
Change of methemoglobin (percent) in venous blood after compared to before treatment with intravenous iron depending on sex.
Measured: 30-120 minutes after start of iron administration
Difference in methemoglobin depending on hemoglobin level before treatment
Change of methemoglobin (percent) in venous blood after compared to before treatment with intravenous iron depending on hemoglobin level before treatment.
Measured: 30-120 minutes after start of iron administration
Difference in methemoglobin depending on blood levels of ferritin, transferrin or iron.
Change of methemoglobin (percent) in venous blood after compared to before treatment with intravenous iron depending on blood levels of ferritin, transferrin or iron.
Measured: 30-120 minutes after start of iron administration
Association between difference in methemoglobin and venous lactate
Association between change of methemoglobin (percent) in venous blood and change of lactate in venous blood after compared to before treatment with intravenous iron.
Measured: 30-120 minutes after start of iron administration
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted13 Mar 2024
- Study start2 Sep 2024
- Primary completion13 Oct 2025
- Study completion13 Oct 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for MethemoglobinemiaStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 50 participants (actual)
Sponsor and investigators
- Lead sponsor
- Claudia Seiler
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor-investigator, Claudia Seiler, Dalarna County Council, Sweden
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06309641
- Sponsor's protocol ID
- MetHb 001
- Status last verified
- Dec 2025
- First submitted
- 7 Mar 2024
- Last updated
- 9 Dec 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 9 Dec 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Methemoglobinemia Following Intravenous Iron Treatment Administered as Ferric Carboxymaltose or Ferric Derisomaltose in Patients With Anemia
- ClinicalTrials.gov ID
- NCT06309641
- Acronym / sponsor ID
- MetHb 001
- Conditions
- Methemoglobinemia, Anemia, Iron Deficiencies, Side Effect
- Keywords
- Intravenous iron, ferric carboxymaltose, ferric derisomaltose
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 50 participants (actual)
- Lead sponsor
- Claudia SeilerUniversity, hospital or other
- Study start
- 2 Sep 2024 (actual)
- Primary completion
- 13 Oct 2025 (actual)
- Study completion
- 13 Oct 2025 (actual)
- First posted
- 13 Mar 2024 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Methemoglobinemia as a side effect of treatment with intravenous iron has not previously been described. This study aims to assess methemoglobin levels in patients with anemia following treatment with intravenous iron, administered as ferric carboxymaltose or ferric derisomaltose.
Detailed description
Methemoglobin is an isoform of hemoglobin without oxygen carrying properties. Higher levels of methemoglobin may impact oxygen transport of the blood and increase the risk of tissue hypoxia. Methemoglobinemia has been reported as side effect of different drugs such as antibiotics or local anesthetics, but not after iron preparations. There is only one case report of increased levels of methemoglobin following intravenous iron therapy.
Patients with anemia due to iron deficiency can be treated with intravenous iron preparations such as ferric carboxymaltose or ferric derisomaltose. Anemia itself reduces oxygen transport of the blood, increasing the risk of tissue hypoxia due to methemoglobinemia in those patients.
This study aims to assess methemoglobinemia following treatment with intravenous iron in patients with anemia. The report will include case reports of patients with severe anemia who developed methemoglobinemia following treatment with ferric derisomaltose. Furthermore, methemoglobin levels are evaluated before and after intravenous iron administration in a cohort of adult patients with anemia who are scheduled to receive ferric carboxymaltose or ferric derisomaltose in routine care.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Number of arms
- 3
| Arm | Type | Receives |
|---|---|---|
| Ferric derisomaltose | – | Diagnostic Test: Blood sample after treatmentAdult patients with anemia scheduled for administration of ferric derisomaltose as prescribed in routine care. |
| Ferric carboxymaltose | – | Diagnostic Test: Blood sample after treatmentAdult patients with anemia scheduled for administration of ferric carboxymaltose as prescribed in routine care. |
| Case reports | – | Other: Case reportsPatients with severe anemia who developed methemoglobinemia after intravenous administration of ferric derisomaltose. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- All adults (age ≥ 18 years) with anemia that are scheduled for administration of intravenous iron (ferric carboxymaltose or ferric derisomaltose) in the region of Dalarna, Sweden.
Key inclusion criteria (5 listed)
- anemia
- prescription of administration of intravenous iron (ferric carboxymaltose or ferric derisomaltose)
- patients with severe anemia who developed methemoglobinemia following administration of ferric derisomaltose
Key exclusion criteria (3 listed)
- declined consent
- known or suspected methemoglobinemia of genetic or other origin
- previous administration of intravenous iron within one week before study sampling.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Blood sample after treatmentBlood samples for measurement of methemoglobin are obtained directly before and 30-120 minutes after drug administration. | Diagnostic test | Ferric carboxymaltose, Ferric derisomaltose |
| Case reportsDescription of clinical course and methemoglobin levels in patients with severe anemia who developed methemoglobinemia after intravenous administration of ferric derisomaltose. | Other | Case reports |
Primary outcome
Difference in methemoglobin after ferric derisomaltose
Time frame: 30-120 minutes after start of iron administration
Change of methemoglobin (percent) in venous blood after compared to before treatment with ferric derisomaltose.
Difference in methemoglobin after ferric carboxymaltose
Time frame: 30-120 minutes after start of iron administration
Change of methemoglobin (percent) in venous blood after compared to before treatment with ferric carboxymaltose.
6 secondary outcomes
Difference in methemoglobin depending on drug dosage
Time frame: 30-120 minutes after start of iron administration
Difference in methemoglobin depending on age
Time frame: 30-120 minutes after start of iron administration
Difference in methemoglobin depending on sex
Time frame: 30-120 minutes after start of iron administration
Difference in methemoglobin depending on hemoglobin level before treatment
Time frame: 30-120 minutes after start of iron administration
Difference in methemoglobin depending on blood levels of ferritin, transferrin or iron.
Time frame: 30-120 minutes after start of iron administration
Association between difference in methemoglobin and venous lactate
Time frame: 30-120 minutes after start of iron administration
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 9 Dec 2025.
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Methemoglobinemia and Anemia, run by Claudia Seiler at 1 site in Sweden.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 5 inclusion and 3 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 9 Dec 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Sweden. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Difference in methemoglobin after ferric derisomaltose (time frame: 30-120 minutes after start of iron administration). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 9 Dec 2025; AzTrials last refreshed its copy on 8 Nov 2026.