Fibromyalgia: should the treatment paradigm be monotherapy or combination pharmacotherapy?

Fibromyalgia (FM) is a disorder characterized by chronic widespread pain, tenderness, and associated symptoms such as fatigue, sleep disturbance, mood disorder, and cognitive dysfunction. Research on the pathophysiology of FM has focused on dysregulation of sensory processing in the central nervous system, as well as genetic and sociobiologic background factors. Abnormalities include excessive pronociceptive input and deficiency of modulatory signaling via noradrenergic and serotonergic pathways. Effective pharmacotherapy of FM includes medications that inhibit pronociceptive input and augment modulatory signaling. Several other dysregulated pathways may be involved and be potential targets for therapeutic intervention. This article reviews positive results of recent monotherapy trials of several norepinephrine and serotonin reuptake inhibitors. Although there has been little assessment of combination therapy in FM, this review outlines the basis for rational treatment using this approach (in order to most effectively treat multiple symptom domains). Controlled monotherapy trials of medications currently being approved for FM demonstrate significant effect on pain, patient global impression of change, and function. Trials are currently being developed to assess the potential additive or synergistic effects of combined central pharmacotherapy and to assess the safety and tolerability of this approach.