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Fibromyalgia (FM)NCT07013305

Pre- and Post-Treatment Investigation of B12 and Folic Acid (Folate) Levels in Patients Receiving Antiepileptic (Anticonvulsant) Treatment for Fibromyalgia: Retrospective Study

An observational study of Fibromyalgia (FM) and Vitamin B 12 Deficiency, run by Gaziosmanpasa Research and Education Hospital at 1 site in Turkey (Türkiye).

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial summary

Fibromyalgia is a rheumatological disorder characterised by chronic widespread body pain, second most common after osteoarthritis. The overall prevalence is 2-8% and it is more common in women. Diffuse body pain, fatigue, sleep and cognitive dysfunction occur. Read more about this study

Who is it for?
Ages 18 to 75 years
How many people
104 participants
Where
1 siteTurkey (Türkiye)
Study dates
11 Jun 2025to 1 Jul 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 to 75 years
  • All sexes
  • No healthy volunteers
  • Adult, Older adult

Study population: Patients who were followed up for 6 months in the physical medicine and rehabilitation clinic with a diagnosis of fibromyalgia and who used antiepileptic (anticonvulsant) drugs will be retrospectively evaluated for the 6 months period (June-December 2024) before the ethics committee approval was obtained. Blood vitamin B12 and folate (folic acid) levels of the patients before and after antiepileptic drug use will be determined. Patients will be evaluated whether there is a change in vitamin B12 and folic acid levels depending on drug use.

Who may be able to join

  • Patients aged 18-75 years who have been diagnosed with fibromyalgia, whose vitamin B12 and folic acid levels have been analysed, who do not receive vitamin B12 and folic acid treatment, and who do not have diabetes mellitus, liver and kidney failure

Who cannot join

  • Patients receiving vitamin B12 and folic acid therapy at the time of antiepileptic (anticonvulsant) drugs initiation, patients with hepatic and renal insufficiency

Trial locations and contacts

1 site in 1 country.

Turkey (Türkiye)1 site

  • Gaziosmanpasa Research and Education Hospital

    Istanbul, Gaziosmanpasa, 34255

Other trials in Turkey (Türkiye)

About this study

Fibromyalgia is a rheumatological disorder characterised by chronic widespread body pain, second most common after osteoarthritis. The overall prevalence is 2-8% and it is more common in women. Diffuse body pain, fatigue, sleep and cognitive dysfunction occur. The etiology of fibromyalgia is multifactorial and occurs due to central and peripheral pain mechanisms that occur with neuroendocrine imbalance due to psychological and physical stress in people with genetic predisposition. The diagnostic criteria for fibromyalgia were updated by the American College of Rheumatology in 2016 to include a widespread body pain scale and a symptom severity scale.

Fibromyalgia treatment consists of drug (antidepressants and antiepileptics) and non-drug treatments. Pregabalin is also used in the treatment of epilepsy by blocking and modulating the α2 δ subunit of voltage-dependent calcium channels. There are studies showing that antiepileptics cause folate and vitamin B12 deficiency in epilepsy patients. In our study, we aimed to retrospectively investigate vitamin B12 and folic acid levels before and after treatment in patients with fibromyalgia using antiepileptics (anticonvulsants).

Read the detailed description

After the acceptance of the study (after obtaining ethics committee approval), patients who have been followed up for at least 6 months in the physical medicine and rehabilitation outpatient clinic with a diagnosis of fibromyalgia and who use pregabalin will be evaluated retrospectively (1-year records). Blood vitamin B12 and folate (folic acid) levels of the patients before and after antiepileptics (anticonvulsants). use will be determined. Patients will be evaluated whether there is a change in vitamin B12 and folic acid levels due to antiepileptics (anticonvulsants) drug use.

Keywords
Antiepileptic (anticonvulsant) drugs, Vitamin D deficiency
Medical subject headings
Fibromyalgia, Vitamin B 12 Deficiency, Folic Acid Deficiency, Vitamin D Deficiency

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Vitamin B12 level analysed before treatment (pre-treatment) (retrospective)

    Vitamin B12 level (pg/mL) among the laboratory parameters analysed before antiepileptic treatment (pre-treatment) for fibromyalgia will be screened retrospectively. Patients who applied to the physical medicine and rehabilitation clinic with a diagnosis of fibromyalgia in the last 6 months (June-December 2024) before the ethics committee application date, who were followed up with this diagnosis and started antiepileptic treatment will be screened within 1 month.

    Measured: Within 1 month

  2. Vitamin B12 level analysed after treatment (post-treatment) (retrospective)

    Vitamin B12 level (pg/mL) among the laboratory parameters analysed after antiepileptic treatment (post-treatment) for fibromyalgia will be screened retrospectively. Patients who applied to the physical medicine and rehabilitation clinic with a diagnosis of fibromyalgia in the last 6 months (June-December 2024) before the ethics committee application date, who were followed up with this diagnosis and started antiepileptic treatment will be screened within 1 month.

    Measured: Within 1 month

  3. Folic acid level analysed before treatment (pre-treatment) (retrospective)

    Folic acid level (ng/mL), one of the laboratory parameters analysed before antiepileptic treatment for fibromyalgia (pre-treatment), will be screened retrospectively. Patients who applied to the physical medicine and rehabilitation clinic with a diagnosis of fibromyalgia in the last 6 months (June-December 2024) before the ethics committee application date, who were followed up with this diagnosis and started antiepileptic treatment will be screened within 1 month.

    Measured: Within 1 month

  4. Folic acid level analysed after treatment (post-treatment) (retrospective)

    Folic acid level (ng/mL), one of the laboratory parameters analysed after antiepileptic treatment for fibromyalgia (post-treatment), will be screened retrospectively. Patients who applied to the physical medicine and rehabilitation clinic with a diagnosis of fibromyalgia in the last 6 months (June-December 2024) before the ethics committee application date, who were followed up with this diagnosis and started antiepileptic treatment will be screened within 1 month.

    Measured: Within 1 month

Secondary outcomes (2)

  1. 25-OH Vitamin D level analysed before treatment (pre-treatment) (retrospective)

    D vitamini (25-OH Vitamin D) (ng/mL) among the laboratory parameters analysed before antiepileptic treatment (pre-treatment) for fibromyalgia will be screened retrospectively. Patients who applied to the physical medicine and rehabilitation clinic with a diagnosis of fibromyalgia in the last 6 months (June-December 2024) before the ethics committee application date, who were followed up with this diagnosis and started antiepileptic treatment will be screened within 1 month.

    Measured: Within 1 month

  2. 25-OH Vitamin D level analysed after treatment (post-treatment) (retrospective)

    25-OH Vitamin D (ng/mL) among the laboratory parameters analysed after antiepileptic treatment (post-treatment) for fibromyalgia will be screened retrospectively. Patients who applied to the physical medicine and rehabilitation clinic with a diagnosis of fibromyalgia in the last 6 months (June-December 2024) before the ethics committee application date, who were followed up with this diagnosis and started antiepileptic treatment will be screened within 1 month.

    Measured: Within 1 month

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted10 Jun 2025
  2. Study start11 Jun 2025
  3. Primary completion25 Jun 2025
  4. Study completion1 Jul 2025

Resources

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
Case crossover
Time perspective
Retrospective
Enrolment
104 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT07013305
Sponsor's protocol ID
03
Status last verified
May 2025
First submitted
21 May 2025
Last updated
26 Jan 2026
Results posted
No
Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No

Publications

  • Mula M, Sander JW. Negative effects of antiepileptic drugs on mood in patients with epilepsy. Drug Saf. 2007;30(7):555-67. doi: 10.2165/00002018-200730070-00001.

    PubMed 17604407

  • Clauw DJ. Fibromyalgia: a clinical review. JAMA. 2014 Apr 16;311(15):1547-55. doi: 10.1001/jama.2014.3266.

    PubMed 24737367

  • Talotta R, Bazzichi L, Di Franco M, Casale R, Batticciotto A, Gerardi MC, Sarzi-Puttini P. One year in review 2017: fibromyalgia. Clin Exp Rheumatol. 2017 May-Jun;35 Suppl 105(3):6-12. Epub 2017 Jun 28.

    PubMed 28681712

  • Aslan K, Bozdemir H, Unsal C, Guvenc B. The effect of antiepileptic drugs on vitamin B12 metabolism. Int J Lab Hematol. 2008 Feb;30(1):26-35. doi: 10.1111/j.1751-553X.2007.00910.x.

    PubMed 18190464

  • Linnebank M, Moskau S, Semmler A, Widman G, Stoffel-Wagner B, Weller M, Elger CE. Antiepileptic drugs interact with folate and vitamin B12 serum levels. Ann Neurol. 2011 Feb;69(2):352-9. doi: 10.1002/ana.22229. Epub 2011 Jan 19.

    PubMed 21246600

Questions about this trial

What is this clinical trial studying?

An observational study of Fibromyalgia (FM) and Vitamin B 12 Deficiency, run by Gaziosmanpasa Research and Education Hospital at 1 site in Turkey (Türkiye).

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 1 inclusion and 1 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 26 Jan 2026. 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 Turkey (Türkiye). 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?

Vitamin B12 level analysed before treatment (pre-treatment) (retrospective) (time frame: Within 1 month). The study lists 4 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT07013305, which also lists 5 linked publications.

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 26 Jan 2026.

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