Brivudine is effective in the early treatment of herpes zoster in immunocompetent adults. Bromovudine is catalyzed by viral thymidine kinase into a monophosphate derivative, which is then converted into a bisphosphate derivative by the progressive action of viral thymidylate kinase, and its triphosphate derivative competitively inhibits the replication of viral DNA. It is effective in the treatment of early herpes zoster. Adverse reactions such as nausea and vomiting may occur after use of the drug, which can usually be gradually relieved after stopping the drug. This medication should not be combined with drugs such as capecitabine, fluorouracil, and tegafur. The use of this drug is prohibited for those who are allergic to this drug or the ingredients in the formulation, patients undergoing chemotherapy for cancer, patients with immunodeficiency, pregnant and lactating women. The specific dosage and usage of the above drugs should follow the doctor’s instructions and should not be used blindly to avoid adverse effects.