oseltamivir phosphateListen to pronunciation(oh-sel-TA-mih-veer FOS-fayt)A drug used to prevent and to treat influenza virus infections. It blocks the release of the virus from infected cells. It is a type of antiviral agent. Also called Tamiflu.Search NCI's Dictionary of Cancer TermsStarts withContainsBrowse:ABCDEFGHIJKLMNOPQRSTUVWXYZ#