Antiviral drugs are a class of medication used specifically for treating viral infections. Like antibiotics, specific antivirals are used in spite of specific viruses. anti viral Antiviral drugs are one class of antimicrobials, a larger group which besides includes antibiotic, antifungal and antiparasitic drugs. They are relatively harmless to the host, and therefore can be used to treat infections. They should be distinguished from viricides, which actively deactivate virus particles exterior the body. Most of the antivirals now available are designed to help deal by HIV; herpes viruses, best known for causing cold sores and genital herpes, but actually causing a wide range of diseases; the hepatitis B and C viruses, which can cause liver cancer; and influenza A and B viruses. Researchers are now working to reach forth the range of antivirals to other families of pathogens. The emergence of antivirals is the product of a greatly expanded attainments of the genetic and molecular function of organisms, allowing biomedical researchers to understand the structure and function of viruses, major advances in the techniques for finding new drugs, and the very great pressure placed on the medical profession to deal with the human immunodeficiency virus (HIV), the cause of the deadly acquired immunodeficiency syndrome (AIDS) pandemic.