ACIVIR 800 DT TABS is an antiviral medication that is used to treat infections caused by herpes viruses, including genital herpes, cold sores, shingles, and chickenpox. It works by stopping the growth and spread of the virus in the body. This medication is available in tablet form and should be taken as directed by a healthcare provider. Common side effects may include nausea, headache, and dizziness. It is important to follow the prescribed dosage and duration of treatment to ensure the medication is effective.