Overview

Fibromyalgia (FM) is a chronic pain syndrome characterized by widespread pain, fatigue, and emotional disorders. Its onset is related to factors such as central sensitization and imbalance of neurotransmitters. The current mainstream treatments include pregabalin, but the efficacy of pregabalin is limited, with only 25%-40% pain relief rate, and adverse reactions are common. Selective serotonin and norepinephrine reuptake inhibitors (SNRIs), such as duloxetine, has demonstrated efficacy in FM by modulating pain pathways through increased serotonin and norepinephrine availability. Several studies have highlighted benefits of venlafaxine in FM. We hypothesize that the combination of pregabalin with venlafaxine may offer greater pain relief compared pregabalin monotherapy, without a significant increase in adverse effects for patients with FM.

Eligibility

Inclusion Criteria:

• Diagnosed with FM according to the 2016 Revisions to the 2010/2011 FM diagnostic criteria;
• Aged more than 18 years;
• Suffering from moderate to severe FM with 11-point numeric rating scale (NRS) score more than 4 at baseline that have not been effectively alleviated by non-pharmacological treatments and has not received currently recommended pharmacological treatment for FM;
• Agreed to sign the informed consent form.

Exclusion criteria

• A history of psychiatric disease;
• Hypersensitivity or have contraindications to pregabalin, venlafaxine;
• Pregnancy or breastfeeding;
• Presence of serious systemic diseases, including uncontrolled hypertension, uncontrolled diabetes, significant cardiac dysfunction, or chronic hepatic or renal dysfunction;
• With acute or chronic pain conditions other than FM.