Vitamin B12 in Association with Antipsychotic Drugs Can Modulate the Expression of Pro-/Anti-Inflammatory Cytokines in Alzheimer Disease Patients

Introduction: Patients with Alzheimer disease (AD) suffer from psychotic symptoms including pain. The current antipsychotic drugs confer limited effectiveness, and hence new strategies are being designed to decrease pain in order to increase antipsychological effectiveness. Vitamin B12 is a safe supplementary drug to decrease pain. Additionally, cytokines participate in the pathogenesis of immune-related diseases such as AD. Thus, the main aim of this clinical trial study was to determine the effects of treatment with risperidone and quetiapine, as antipsychotic drugs, with and without vitamin B12 on the psychotic symptoms of AD patients and the expression of IL-6, IL-8, tumor growth factor (TGF)-β, tumor necrosis factor (TNF)-α, and endothelin (ET)-1). Material and Methods: Serum levels of IL-6, IL-8, TGF-β, TNF-α, and ET-1 were evaluated in the following groups: healthy controls, nonpsychotic AD patients, psychotic AD patients, psychotic AD patients under treatment with risperidone, psychotic AD patients under treatment with risperidone plus vitamin B12, psychotic AD patients under treatment with quetiapine, and psychotic AD patients under treatment with quetiapine plus vitamin B12. Results: Treatment with antipsychotic drugs plus vitamin B12 led to a decreased expression of IL-8 and TNF-α and an increased expression of TGF-β. Vitamin B12 in association with quetiapine reduced the pain in psychotic AD patients. Discussion: Proinflammatory cytokines play important roles in the pathogenesis of psychosis in AD patients. Antipsychotic drugs plus vitamin B12 can reduce and induce the expression of proinflammatory and anti-inflammatory cytokines to improve psychotic symptoms in AD patients.