Neuropathic PainNCT07013318
Pre- and Post-Treatment Investigation of B12 and Folic Acid (Folate) Levels in Patients Receiving Antiepileptic (Anticonvulsant) Treatment for Neuropathic Pain
An observational study of Neuropathic Pain and Vitamin B 12 Deficiency, run by Gaziosmanpasa Research and Education Hospital at 1 site in Turkey (Türkiye).
Trial summary
Neuropathic pain (NeP) is a disorder of the nervous system resulting from altered mechanisms operating at the peripheral nervous system, spinal cord and supraspinal levels and is defined by the International Association for the Study of Pain as pain resulting from nervous system pathologies that cause changes in the… Read more about this study
- Who is it for?
- Ages 18 to 90 years
- Conditions the study is for
- Neuropathic Pain, Vitamin B 12 Deficiency
- How many people
- 96 participants
- Where
- 1 siteTurkey (Türkiye)
- Study dates
- 15 Jun 2025to 5 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 90 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 neuropathic pain 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 18-90 years who have been diagnosed with neuropathic pain, 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
About this study
Official title: Pre- and Post-Treatment Investigation of B12 and Folic Acid (Folate) Levels in Patients Receiving Antiepileptic (Anticonvulsant) Treatment for Neuropathic Pain: Retrospective Study
Neuropathic pain (NeP) is a disorder of the nervous system resulting from altered mechanisms operating at the peripheral nervous system, spinal cord and supraspinal levels and is defined by the International Association for the Study of Pain as pain resulting from nervous system pathologies that cause changes in the function, chemistry and structure of neurons . NeP affects 2-8% of the world population and can have a significant impact on the patient's functional abilities and quality of life. NeP can be caused by spinal cord injury, brain and spinal cord tumours and other diseases affecting the nervous system. NeP can be secondary to extremely common conditions such as diabetes, stroke, cancer, herpes zoster virus infection and autoimmune disease. These recommendations were finalised in 2019 and published in April 2020. Following the GRADE system, the recommendations suggest first-line treatment options including serotonin-noradrenaline reuptake inhibitors (duloxetine and venlafaxine), gabapentin, tricyclic antidepressants, and the specialised use of topical lidocaine and transcutaneous electrical nerve stimulation for peripheral neuropathic pain. Pregabalin, tramadol and combination therapy (combining antidepressants with gabapentinoids) are recommended as second-line treatments. Highly concentrated capsaicin patches and botulinum toxin A are recommended as second-line treatments, especially for focal peripheral neuropathic pain. Third-line treatment options include high-frequency repetitive transcranial magnetic stimulation (rTMS) of the primary motor cortex (motor cotex-1/M1), spinal cord stimulation (for failed back surgery syndrome and painful diabetic polyneuropathy) and strong opioids as a last resort in the absence of alternatives. In addition, psychotherapy, including cognitive behavioural therapy and mindfulness, is recommended as second-line treatment in combination with other therapies.
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 analyse vitamin B12 and folic acid levels before and after treatment in patients using antiepileptics (anticonvulsants) for neuropathic pain.
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 neuropathic pain 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 pregabalin use will be determined. Patients will be evaluated whether there is a change in vitamin B12 and folic acid levels due to drug use.
- Conditions
- Neuropathic Pain, Vitamin B 12 Deficiency
- Keywords
- antiepileptic drug, folic acid
- Medical subject headings
- Neuralgia, Vitamin B 12 Deficiency
What is being measured
The primary outcome is the main question the study is designed to answer.
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 neuropathic pain will be screened retrospectively. Patients who applied to the physical medicine and rehabilitation clinic with a diagnosis of neuropathic pain 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
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 neuropathic pain will be screened retrospectively. Patients who applied to the physical medicine and rehabilitation clinic with a diagnosis of neuropathic pain 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
Folic acid level analysed before treatment (pre-treatment) (retrospective)
Folic acid level (ng/mL), one of the laboratory parameters analysed before antiepileptic treatment for neuropathic pain (pre-treatment), will be screened retrospectively. Patients who applied to the physical medicine and rehabilitation clinic with a diagnosis of neuropathic pain 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
Folic acid level analysed after treatment (post-treatment) (retrospective)
Folic acid level (ng/mL), one of the laboratory parameters analysed after antiepileptic treatment for neuropathic pain (post-treatment), will be screened retrospectively. Patients who applied to the physical medicine and rehabilitation clinic with a diagnosis of neuropathic pain 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)
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 neuropathic pain will be screened retrospectively. Patients who applied to the physical medicine and rehabilitation clinic with a diagnosis of neuropathic pain 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
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 neuropathic pain will be screened retrospectively. Patients who applied to the physical medicine and rehabilitation clinic with a diagnosis of neuropathic pain 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.
- First posted10 Jun 2025
- Study start15 Jun 2025
- Primary completion25 Jun 2025
- Study completion5 Jul 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (3)Papers the sponsor has linked to this study.
- Other trials for Neuropathic PainStudies 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
- Case crossover
- Time perspective
- Retrospective
- Enrolment
- 96 participants (actual)
Sponsor and investigators
- Lead sponsor
- Gaziosmanpasa Research and Education Hospital
- Sponsor type
- Other government
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07013318
- Sponsor's protocol ID
- 85
- Status last verified
- May 2025
- First submitted
- 21 May 2025
- Last updated
- 30 Sep 2025
- 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 17604407Aslan 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 18190464Linnebank 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
Study at a glance
From the registry record, last updated by the sponsor on 30 Sep 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Pre- and Post-Treatment Investigation of B12 and Folic Acid (Folate) Levels in Patients Receiving Antiepileptic (Anticonvulsant) Treatment for Neuropathic Pain: Retrospective Study
- ClinicalTrials.gov ID
- NCT07013318
- Acronym / sponsor ID
- 85
- Conditions
- Neuropathic Pain, Vitamin B 12 Deficiency
- Keywords
- antiepileptic drug, folic acid
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 96 participants (actual)
- Lead sponsor
- Gaziosmanpasa Research and Education HospitalOther government
- Study start
- 15 Jun 2025 (actual)
- Primary completion
- 25 Jun 2025 (actual)
- Study completion
- 5 Jul 2025 (actual)
- First posted
- 10 Jun 2025 (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.
Neuropathic pain (NeP) is a disorder of the nervous system resulting from altered mechanisms operating at the peripheral nervous system, spinal cord and supraspinal levels and is defined by the International Association for the Study of Pain as pain resulting from nervous system pathologies that cause changes in the function, chemistry and structure of neurons . NeP affects 2-8% of the world population and can have a significant impact on the patient's functional abilities and quality of life. NeP can be caused by spinal cord injury, brain and spinal cord tumours and other diseases affecting the nervous system. NeP can be secondary to extremely common conditions such as diabetes, stroke, cancer, herpes zoster virus infection and autoimmune disease. These recommendations were finalised in 2019 and published in April 2020. Following the GRADE system, the recommendations suggest first-line treatment options including serotonin-noradrenaline reuptake inhibitors (duloxetine and venlafaxine), gabapentin, tricyclic antidepressants, and the specialised use of topical lidocaine and transcutaneous electrical nerve stimulation for peripheral neuropathic pain. Pregabalin, tramadol and combination therapy (combining antidepressants with gabapentinoids) are recommended as second-line treatments. Highly concentrated capsaicin patches and botulinum toxin A are recommended as second-line treatments, especially for focal peripheral neuropathic pain. Third-line treatment options include high-frequency repetitive transcranial magnetic stimulation (rTMS) of the primary motor cortex (motor cotex-1/M1), spinal cord stimulation (for failed back surgery syndrome and painful diabetic polyneuropathy) and strong opioids as a last resort in the absence of alternatives. In addition, psychotherapy, including cognitive behavioural therapy and mindfulness, is recommended as second-line treatment in combination with other therapies.
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 analyse vitamin B12 and folic acid levels before and after treatment in patients using antiepileptics (anticonvulsants) for neuropathic pain.
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 neuropathic pain 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 pregabalin use will be determined. Patients will be evaluated whether there is a change in vitamin B12 and folic acid levels due to drug use.
Study design
- Observational model
- Case crossover
- Time perspective
- Retrospective
Who may qualify
- Ages
- 18 to 90 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- Patients who were followed up for 6 months in the physical medicine and rehabilitation clinic with a diagnosis of neuropathic pain 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.
Key inclusion criteria (1 listed)
- Patients aged 18-90 years who have been diagnosed with neuropathic pain, 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
Key exclusion criteria (1 listed)
- Patients receiving vitamin B12 and folic acid therapy at the time of antiepileptic (anticonvulsant) drugs initiation, patients with hepatic and renal insufficiency
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
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 neuropathic pain will be screened retrospectively. Patients who applied to the physical medicine and rehabilitation clinic with a diagnosis of neuropathic pain 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.
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 neuropathic pain will be screened retrospectively. Patients who applied to the physical medicine and rehabilitation clinic with a diagnosis of neuropathic pain 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.
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 neuropathic pain (pre-treatment), will be screened retrospectively. Patients who applied to the physical medicine and rehabilitation clinic with a diagnosis of neuropathic pain 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.
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 neuropathic pain (post-treatment), will be screened retrospectively. Patients who applied to the physical medicine and rehabilitation clinic with a diagnosis of neuropathic pain 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 secondary outcomes
25-OH Vitamin D level analysed before treatment (pre-treatment) (retrospective)
Time frame: Within 1 month
25-OH Vitamin D level analysed after treatment (post-treatment) (retrospective)
Time frame: Within 1 month
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 30 Sep 2025.
- Background: PubMed 17604407Mula 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.
- Results publication: PubMed 18190464Aslan 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.
- Results publication: PubMed 21246600Linnebank 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.
Related trials for Neuropathic Pain
RecruitingObservational study
Pain Phenotypes in Individuals With Multiple Sclerosis
Multiple Sclerosis, Chronic Pain
Enrolling by invitationPhase 4
Low Dose Naltrexone Therapy for Complex Regional Pain Syndrome
Complex Regional Pain Syndrome, Chronic Pain
RecruitingPhase 2
Effectiveness of Phenotype-based Pain Management Guidelines for Head and Neck Cancer Related Pain: a Pilot Study
Cancer Pain, Orofacial Pain
RecruitingPhase 2
A Master Protocol Study (LY900028) of Multiple Intervention-Specific-Appendices (ISAs) in Participants With Chronic Pain
Osteoarthritis, Knee, Diabetic Neuropathic Pain
RecruitingObservational study
Trigeminal Neuralgia Electrophysiology
Trigeminal Neuralgia
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 Neuropathic Pain 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 30 Sep 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 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 NCT07013318, which also lists 3 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 30 Sep 2025.