The Effect of Minocycline and N-acetylcysteine for the Treatment of Fibromyalgia

Inclusion Criteria * Female * Age 18 years or older * Diagnosis of fibromyalgia for at least 6 months (confirmed by the modified 2010 ACR Diagnostic Criteria for Fibromyalgia Widespread Pain Inventory and Symptom Severity Scale) * Currently on birth control or unable to become pregnant * Willingness to avoid taking opioid and opiate medications during the duration of the study (5-6 months) Exclusion Criteria * Known hypersensitivity to minocycline or tetracycline antibiotics or to N-acetylcysteine * Current opioid therapy or planned initiation of opioid therapy * Active pregnancy, lactation or plans to become pregnant in the next 6 months * Significant hepatic disease as indicated by an AST or ALT greater than twice the upper limits of normal or bilirubin greater than twice the upper limits of normal * Significant renal disease as indicated by an estimated glomerular filtration rate less than 60 mL/min/1.73m2 at baseline or during the first washout period * History of autoimmune syndromes (systemic lupus erythematosus, myasthenia gravis, rheumatoid arthritis, * History of intracranial hypertension or pseudotumor cerebri * History of IBD (Crohns disease, ulcerative colitis), Clostridium difficile infection * History of esophagitis, esophageal obstruction, achalasia or esophageal dysmotility * History of GI hemorrhage or known risk factors for GI hemorrhage, such as esophageal varices, peptic ulcer disease, etc. * Subjects taking divalent and trivalent cations such as oral iron supplements, certain dietary supplements (multivitamins) that contain manganese or zinc, or antacids that contain aluminum, calcium, or magnesium, which would decrease minocycline absorption * Subjects taking anticoagulant medication since minocycline can decrease plasma prothrombin activity * Subjects taking isotretinoin * Subject taking ergot alkaloids for migraines * Subjects taking penicillin antibiotics * Subjects taking methoxyflurane containing products * Subjects who work outdoors or otherwise have prolonged exposure to UV light and sunlight * Lack of access to reliable technology to be able to complete emailed REDCap questionnaires * Cognitive deficits that may make it difficult to adhere to the medication regimen or provide consistent and timely completion of questionnaires * Inability or unwillingness to give informed consent * Unwillingness to use two forms of birth control for the entire duration of participation in the study (if capable of becoming pregnant) * Unwillingness to complete home pregnancy tests throughout the study (if capable of becoming pregnant) * Inability to swallow large pills