The efficacy and effect of Famciclovir Tablets is mainly to inhibit herpes simplex virus type I and II and varicella zoster virus, the specific use of medication as prescribed by the doctor. Famciclovir Tablets can be rapidly converted into Penciclovir in the body, the latter can inhibit herpes simplex viruses of types I and II and varicella zoster virus, and is indicated for the treatment of herpes zoster and primary genital herpes. It should be contraindicated in people who are allergic to the product and to Penciclovir. Common adverse reactions after use are headache and nausea, in addition to dizziness, insomnia, drowsiness, diarrhea, abdominal pain, dyspepsia, anorexia, fatigue, pain, fever, chills, rash, itchy skin, and other adverse reactions can be seen. Note that patients with renal insufficiency should pay attention to adjust the dosage. Specific medication should be under the guidance of a specialist, not unauthorized use of medication.