Overview
Fibromyalgia is a chronic pain syndrome where current medications have limited efficacy and a slow onset of action. Esketamine shows potential as a rapid-acting analgesic, but previous low-dose studies failed to demonstrate long-term benefits. The efficacy of higher-dose ESK as an adjunctive therapy when standard treatments are insufficient remains unclear.
Eligibility
Inclusion Criteria:
- Patients between ages over 18 years with proper cognitive function and language skills for the study;
- Patients diagnosed with FM as defined by the ACR FM diagnostic criteria;
- Patients who have experienced insufficient symptom relief with non-pharmacological treatments and have not previously received recommended pharmacological treatment for FM;
- A score of ≥ 4 on the average pain intensity over 7 days on the numeric rating scale (NRS) at baseline.
Exclusion criteria:
- Patient refusal;
- Inability to sign informed consent;
- Had other secondary FM, this is, hypothyroidism, nutritional deficiency, diabetes mellitus, connective tissue disorder;
- Had psychiatric disorder, this is, schizophrenia and other psychotic disorder, bipolar disorder, or personality disorder;
- Obstructive sleep apnea syndrome or a STOP-Bang score ≥ 3;
- History of treatment with pregabalin and/or venlafaxine for any disease;
- History of treatment with intravenous ketamine or ESK for chronic pain;
- Presence of other painful ailments such as inflammatory rheumatic disease;
- Uncontrolled diabetes, refractory hypertension, malignancies, narrow-angle glaucoma, hyperthyroidism, severe cardiovascular disease or any other contraindications to esketamine;
- History of prescription drug abuse, alcoholism or illicit drug use;
- Pregnant or lactating women;
- Allergic to any of the study drugs.