Famciclovir capsules are an antiviral drug used primarily for the treatment of herpes zoster and genital herpes. The efficacy of famciclovir capsules in preventing recurrence of genital herpes, ocular herpes zoster, disseminated herpes zoster, and herpes in immunodeficient patients has not been confirmed; therefore, famciclovir capsules do not treat these diseases, and genital herpes is not completely cured. It is also unclear whether famciclovir can prevent the spread of the disease. Genital herpes can be transmitted through sexual contact, so sexual contact must be avoided during treatment. For patients with renal insufficiency, you should see your doctor to adjust the usage and dosage when using famciclovir, but no dosage adjustment is needed for patients with compensated liver disease. The most common adverse reactions when taking famciclovir capsules are headache and nausea, as well as other side effects.