The United States is set to increase its manufacturing of amoxicillin — a widely used prescription antibiotic that recently faced a national shortage — after Walmart and medical supply and distribution company McKesson inked a deal with the nation's lone manufacturer of the drug.  "We are thrilled to work with Walmart and McKesson to bring domestically manufactured antibiotics directly to American families," Patrick Cashman, president of USAntibiotics, said in a press release of the announcement on Monday.  ...