The Efficacy and Safety of Short Term S-ketamine Infusion as an Adjunctive Therapy in Patients With Fibromyalgia

Comparing the Efficacy and Safety of Conventional Therapy With Conventional Therapy Combined Esketamine in the Treatment of Fibromyalgia: A Multicenter Clinical Study

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.

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.