Efficacy and Safety of Brivudine in the Treatment of Herpes Zoster

Inclusion Criteria:

1. Age ≥18 years, regardless of gender;

2. Signed Informed Consent Form;

3. Female subjects must not plan for pregnancy or oocyte donation from screening until 1 week after the last dose and must voluntarily adopt highly effective physicalcontraception; male subjects must not plan for fertility or sperm donation duringthe same period and must voluntarily adopt highly effective physical contraception.Methods include:

• Barrier methods: Condom or barrier cap (diaphragm or cervical cap);

• Intrauterine device (IUD) or intrauterine system (IUS);

• Surgical sterilization (bilateral oophorectomy with/without hysterectomy, totalhysterectomy, bilateral tubal ligation, or vasectomy) performed ≥6 months priorto the first dose in the subject or their partner;

• Other investigator-confirmed highly effective physical contraception.

Exclusion Criteria:

1. Allergy to brivudine, famciclovir, or penciclovir;

2. Current use of fluorouracil agents (e.g., 5-fluorouracil, capecitabine, tegafur,flucytosine);

3. Cancer patients currently undergoing chemotherapy;

4. Pregnant or lactating women;

5. Parkinson's disease;

6. Any condition deemed inappropriate for study participation by the investigator.