When methylcobalamin is not effective in patients with peripheral neuritis, the cause of the condition needs to be treated as well as symptomatically with other medications. Most of the causes of peripheral neuritis are clear, including infections, immunological factors, metabolic factors, heredity, tumors, drug poisons, nerve compression and so on. 1. Treatment for the cause: for example, if peripheral neuritis is caused by poisoning, it should be treated with antidote immediately; if peripheral neuritis is caused by diabetes mellitus, strict control of blood glucose is also needed. 2. Symptomatic treatment: Generally, medication is the mainstay of treatment, including immunomodulating drugs, nutritive nerve drugs, pain relieving drugs. (1) Immunomodulatory drugs: such as glucocorticoids, immunoglobulins, etc. They can inhibit the immune response and anti-inflammatory. They can inhibit immune response and anti-inflammatory. (2) Nutritional nerve drugs: such as vitamin B1, B6, B12 and so on. It can promote the recovery of damaged nerves. (3) pain medication: such as local use of lidocaine-containing compresses, the main role is to relieve pain. Peripheral neuritis eating methylcobalamin is ineffective, should promptly go to the hospital neurology department, and under the guidance of the doctor for treatment. Drugs should all be used under the guidance of a doctor.