Antiviral therapy: old and current issues.

Many antiviral drugs are currently approved and formally licensed for clinical use in the treatment of viral infections caused by human immunodeficiency virus, herpes simplex viruses, varicella-zoster virus, respiratory syncytial virus, cytomegalovirus, hepatitis B virus, hepatitis C virus or influenza virus. Recent decades have seen major advances in our knowledge of the natural history and pathogenesis of viral diseases as well as ongoing developments and improvements in antiviral therapy. However, research is far from complete and indeed previously unknown and unexpected issues are currently arising. This review aims to discuss some of these issues in the belief that they should be carefully addressed to enhance the management of patients with viral infections.