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NCT Number: NCT07013305

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

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Key information

Conditions

Fibromyalgia (FM) Avitaminosis Deficiency Diseases Fibromyalgia Folic Acid Deficiency Malnutrition Muscular Diseases Musculoskeletal Diseases Nervous System Diseases Neuromuscular Diseases Nutrition Disorders Nutritional and Metabolic Diseases Rheumatic Diseases Vitamin B 12 Deficiency Vitamin B Deficiency Vitamin D Deficiency

Age range

18 year–75 year

Sex eligibility

All sexes

Study type

Observational

Primary location

Gaziosmanpasa Research and Education Hospital

Istanbul, Gaziosmanpasa, 34255, Turkey (Türkiye)

About this study

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.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • 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

Exclusion criteria

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

Treatment and study plan

Primary outcomes

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

    Time frame: Within 1 month

    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.

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

    Time frame: Within 1 month

    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.

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

    Time frame: Within 1 month

    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.

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

    Time frame: Within 1 month

    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.

Secondary outcomes

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

    Time frame: Within 1 month

    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.

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

    Time frame: Within 1 month

    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.

Sponsors and collaborators

Lead sponsor

Gaziosmanpasa Research and Education Hospital

Other Gov

Registry information

Important dates

Study start
2025
Primary completion
2025
Study completion
2025
First posted
Jun 10, 2025
Registry last updated
Jan 26, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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