Famciclovir capsules themselves belong to the class of antiviral drugs, which have a certain inhibitory effect on the herpes virus. After entering the body, the drug can effectively destroy the cellular structure of the herpes virus, thus inhibiting the activity of the herpes virus and further killing the herpes virus. It can effectively reduce the number of blisters, dry up and crust, shorten the duration of the disease, and thus achieve the therapeutic effect. However, it is important to note that after a period of discontinuation, the tolerance will gradually disappear and re-exposure to the herpes virus may lead to re-infection. In addition to oral famciclovir, topical penciclovir can be used as a combination treatment.