Flupirtine is used as an analgesic for acute and chronic pain, in moderate to severe cases. Mass by mass flupirtine has approximately one third the analgesic potency of codeine. Its muscle relaxant properties make it popular for back pain and other orthopaedic uses, but it is also used for migraines, in oncology, postoperative care, and gynaecology. Flupirtine has been noted for its neuro-protective properties, and it is being investigated for possible use in Creutzfeld-Jakob disease, Alzheimer's disease, and multiple sclerosis. It has also been proposed as a possible treatment for Batten disease. Flupirtine underwent a clinical trial as a treatment for multiple sclerosis and fibromyalgia. Flupirtine is notably devoid of any addictive properties, negative psychological or motor function effects, or effects on reproductive function. Drug tolerance does not develop in most cases; however, tolerance may develop in single cases.