ASSOCIATED PRESS WASHINGTON -- The Food and Drug Administration warned Friday that three asthma drugs may increase the risk of severe asthma attacks and even death. The agency asked the manufacturers of Advair, Serevent and Foradil to strengthen the warning labels to reflect this risk. The FDA said that even though the drugs decrease the frequency of asthma attacks, they can make the attacks more severe when they occur. The agency said the drugs should be prescribed only if other medicines do not control patients' asthma. Advair had sales of $4.7 billion in 2004, making it one of GlaxoSmithKline's top-selling...