Brain Response to Single Dose of Pregabalin in Fibromyalgia

• Status: Completed
• Trial end date: 2017-01-01
• Target enrollment: 0
• Participant gender: Female

Summary

Fibromyalgia syndrome represents a "spectrum disorder" characterized by widespread chronic pain, fatigue, sleep disturbances, mood and cognitive alterations. The most accepted models explaining the causes of the disease have focused on the reduced pain inhibitory systems activity, that allow low intensity stimuli to be processed easier, and that finally amplify pain stimuli. One of the interventions approved for Fibromyalgia is Pregabalin, which demonstrated to be effective reducing pain. Different studies in animals have shown that it works reducing the liberation of neuronal messengers, which slow the conduction of pain signals. Although studies in humans have confirmed Pregabalin clinical benefits, there are still few studies aiming to explain how it actually works in patients with fibromyalgia, though.

A better understanding of the mechanisms by which Pregabalin reduces pain in patients with fibromyalgia would allow designing new interventions to enhance its clinical effects. Thus, the investigators propose to study in real-time the electrical, vascular and hormonal response of the brain of patients with fibromyalgia who receive a single dose of Pregabalin. The vascular response will be assessed using functional near infrared spectroscopy (fNIRS) neuroimaging techniques. The electrical response will be assessed using Transcranial Magnetic Stimulation (TMS). The hormonal response will be assessed in blood, measuring neurotrophins (Brain Derived Neurotrophic Factor) and inflammatory mediators (Tumor Necrosis Factor). These responses will be studied in consideration of the patients' characteristics that will be assessed using validated scales.

Taken into account the above considerations, a crossover, double-blinded randomized clinical trial is proposed. In the investigators' study, patients and healthy volunteers will be asked to visit the investigators' laboratory in three opportunities: one for a baseline assessment, and the other two to test the effects of either Pregabalin 150 mg PO or Placebo. All participants will eventually receive both, Pregabalin and Placebo. In each visit a brain hemodynamic, electrical, hormonal and clinical evaluation will be performed.

• Phase: Phase 2/Phase 3
• Accepts Healthy Volunteers?: Accepts Healthy Volunteers

Details

• Lead Sponsor: Hospital de Clinicas de Porto Alegre
• Collaborators: Conselho Nacional de Desenvolvimento Científico e Tecnológico; Coordenação de Aperfeiçoamento de Pessoal de Nível Superior.; Fundação de Amparo à Pesquisa do Estado do Rio Grande do Sul, Brazil
• Treatments: Pregabalin

Criteria

Inclusion Criteria:

• Fulfill ACR 2010 criteria for fibromyalgia diagnosis.

• Literate.

• Mean VAS for pain higher than 6 in the last 3 months.

Exclusion Criteria:

• Pregnancy or inadequate use of validated contraceptive method.

• Contraindications for Transcranial Magnetic Stimulation.

• Alcohol of drugs abuse in the last 6 months.

• Any severe neurological, neurosurgical, cardiac, endocrinological, or oncological disease (current or past).

• Decompensated chronic systemic disease.

• Previous use of Pregabalin.