Mecobalamin can be used to treat vocal cord paralysis due to peripheral neuropathy, but the efficacy varies from person to person. 1. Indications: It can be used for the treatment of megaloblastic anemia caused by vitamin B12 deficiency, and can also be used for the treatment of peripheral neuropathy, if the vocal cord paralysis is caused by peripheral neuropathy, the drug may have a certain effect. 2. Adverse reactions: Of the total 15,180 cases, 146 cases (0.96%) had adverse reactions. (At the end of the investigation of the frequency of adverse reactions) Gastrointestinal: occasional (5%~0.1%) loss of appetite, nausea, vomiting, diarrhea; allergy: rare (<0.1%) rash, did not see a drop in blood pressure, respiratory distress. 3. Contraindications: allergy to drug components, children, lactation, pregnancy, people are advised to use the drug with caution. Methylcobalamin needs to be used under the guidance of clinicians, avoid self-medication.