Antibiotics don't help fight most sinus infections, although doctors routinely prescribe them for that purpose, according to a U.S. study. Researchers whose work was published in the Journal of the American Medical Association found that antibiotics didn't ease patients' symptoms or get them back to work any sooner than an inactive placebo pill. Antibiotics are known to fuel the evolution of drug-resistant bacteria and experts have grown increasingly worried about overuse. This is a particular concern with sinus infections, because doctors can't tell if the disease is caused by bacteria or by a virus, in which case antibiotics are useless....