Vitamin B6 and B12 in the Treatment of Movement Disorders Induced by Antipsychotics

D2 dopaminergic receptor blockers, used to treat schizophrenia, can lead to the onset of drug-induced movement disorders, such as parkinsonism, dystonia, dyskinesia and akathisia. They seem to be associated with oxidative stress, as a result of an increase in free radicals generated from dopamine metabolism. A preclinical study showed that vitamin B6 (pyridoxine) and B12 (cobalamin), alone or in combination, prevented the development of orofacial dyskinesia induced by haloperidol in an animal model of schizophrenia.

Specific Aim1: To conduct a prospective, randomized, double-blind, placebo-controlled trial to evaluate the efficacy of 12-week adjuvant treatment with 200mg of pyridoxine (B6) or 2mg of cobalamin (B12) to treat drug-induced movement disorders of patients with schizophrenia, schizoaffective or bipolar disorder. The investigators will randomly assign 45 patients into three groups: placebo, B6 or B12 and check whether administration of vitamin B6 (pyridoxine) or B12 (cobalamin) attenuates drug-induced movement disorders (IDDM) in patients with diagnosis of schizophrenia, schizoaffective or bipolar disorder.

Specific Aim 2: To quantify changes in serum markers of inflammation and biomarkers of oxidative stress in response to adjunctive treatment with B6 or B12. The hypothesis is that changes in these biomarkers will mediate the clinical response to them.

Research Plan: The investigators will carry out a proof of concept 12-week prospective, randomized, double-blind, controlled trial of vitamin B6 and B12, at doses of 200 mg/day and 2mg/day, respectively, or identical placebo tablets, added to ongoing antipsychotics in 45 stable patients (ages 18-60 years, 15 patients per group) with diagnosis of schizophrenia, schizoaffective or bipolar disorder. The study will be conducted at the Drug Research and Development Center (NPDM), at the Universidade Federal do Ceará, Fortaleza, Brazil. This center has a long history of performing placebocontrolled trials in clinical medicine (http://www.npdm.ufc.br/) and has the necessary infrastructure to successfully complete the proposed study protocol. All participants will give written informed consent prior to study enrollment.

• Pyridoxine (Drug), also known as Vitamin B6: Adjuvant daily treatment with 200mg of pyridoxine
• Cobalamin (Drug), also known as Vitamin B12: Adjuvant daily treatment with 2mg of cobalamin
• Placebo Oral Tablet (Drug): Adjuvant daily treatment with placebo

Primary outcomes

• Change in the Simpson-Angus Extrapyramidal Symptoms Scale (SAS) scores [Baseline and 12 weeks]: 10-item rating scale to assess extrapyramidal symptoms; each item is scored 0-4, yielding a total between 0 and 40.
• Change in the Barnes Akathisia Rating Scale (BAS, BARS) scores [Baseline and 12 weeks]: Objective Akathisia, Subjective Awareness of Restlessness and Subjective Distress Related to Restlessness are rated on a 4-point scale from 0 - 3 and are summed yielding a total score ranging from 0 to 9. The Global Clinical Assessment of Akathisia uses a 5-point scale ranging from 0 - 4.
• Change in the Abnormal Involuntary Movement Scale (AIMS) scores [Baseline and 12 weeks]: 10-item rating scale to assess involuntary movements; items are rated on a five-point scale of severity from 0-4, yielding a total between 0 and 40.

Secondary outcomes

• Change in the Brief Psychiatry Rating Scale (BPRS) scores [Baseline and 12 weeks]: 18-item rating scale to assess changes in psychopathology; each item is scored 0-6, yielding a total between 0 and 40.
• Change in Plasma Glutathione (GSH) [Baseline and 12 weeks]: GSH in ng/mL
• Change in serum level of Nitrite [Baseline and 12 weeks]: Nitrite in nanomole/mililiter
• Change in serum level of Thiobarbituric acid reactive substances (TBARS) [Baseline and 12 weeks]: TBARS in mmol of malonaldehyde/mL
• Change in serum level of Interleukin 1 β (IL-1β) [Baseline and 12 weeks]: IL-1β in pg/mL
• Change in serum level of Interleukin-4 [Baseline and 12 weeks]: IL-4 in pg/mL
• Change in serum level of Interferon gamma (IFNγ) [Baseline and 12 weeks]: IFNγ in pg/mL
• Change in serum level of Tumor necrosis factor alpha (TNF-α) [Baseline and 12 weeks]: TNF-α in pg/mL
• Change in Indoleamine 2,3-dioxygenase (IDO) enzymatic activity [Baseline and 12 weeks]: IDO activity in U IDO mol\^-1/mg\^-1

Sex: All, ages: 18 Years to 60 Years

Inclusion Criteria:

* Capacity to provide informed consent;
* Schizophrenia diagnosis (confirmed by Structured Clinical Interview (SCID);
* Movement disorders induced by psychotropic drugs of at least moderate severity;
* Exposure to psychotropic medication for at least three months prior of the appearance of movement disorders;.
* Disorders of movement for at least one year;
* Stable psychotropic regimen for at least one month prior to study entry.

Exclusion Criteria:

* 6-month history of any drug or alcohol abuse or dependence;
* Changes in psychotropic medications within the last 4 weeks;
* General medical illness including autoimmune disorders, known chronic infections such as HIV or hepatitis C, and liver or renal failure that could adversely impact on patient outcome;
* Women who are planning to become pregnant, are pregnant, or are breastfeeding.

• Lia LO Sanders, MD, PhD, Principal investigator, Núcleo de Pesquisa e Desenvolvimento de Medicamentos