Zovirax 200 Tablet contains Acyclovir 200 mg, an antiviral agent primarily indicated for the treatment of herpes simplex virus infections, including genital herpes, cold sores, and shingles (herpes zoster). Acyclovir acts by inhibiting viral DNA synthesis, thereby preventing viral replication and reducing the severity and duration of outbreaks. It is also used in the management of varicella (chickenpox) and for prophylaxis in immunocompromised patients to prevent cytomegalovirus infections. Zovirax 200 Tablet is administered orally, with dosage and duration tailored according to the specific infection and patient condition. Common side effects may include headache, nausea, diarrhea, and abdominal discomfort; however, it is generally well tolerated. Caution is advised in patients with renal impairment, and adequate hydration should be maintained to prevent nephrotoxicity. Use during pregnancy and lactation should be under medical supervision. Zovirax 200 Tablet should be used strictly as prescribed, and patients are advised to complete the full course of therapy even if symptoms improve to prevent viral resistance and recurrence. This medication is not effective against bacterial infections and should not be used for prophylaxis without medical indication.