From the FDA: Consumer Questions and Answers about Flu Medicines

The term “influenza” refers to illness caused by influenza virus. This is commonly also called “flu,” but many different illnesses cause “flu-like” systemic and respiratory symptoms such as fever, chills, aches and pains, cough, and sore throat. In addition, influenza itself can cause many different illness patterns, ranging from mild common cold symptoms to typical “flu” to life-threatening pneumonia and other complications, including secondary bacterial infections. The main focus of the following web pages is on the drugs approved by FDA for the treatment and prevention of influenza. Because vaccination is the primary means of preventing and controlling influenza, links are also provided to information pertaining to vaccines. For additional updates and comprehensive information about flu, please go to http://www.cdc.gov/flu/. Information provided on this web site may change frequently, and should not be used as a substitute for individual evaluation by a health care provider, or as the primary means of diagnosing influenza or determining treatment. Read about Tamiflu Read about Relenza