Louisville-based Humana is suing a company for using a name similar to that of one of its partners that has caused the healthcare company to be criticized for controversial comments made by radio talk show host Rush Limbaugh.The comments were made about a Georgetown law student and her use of contraception. Limbaugh has since apologized but has lost some two dozen advertisers.Humana doesn’t advertise on the radio, and has never supported Limbaugh’s show, but an ad aired during his program using the name Concentra to market memory aid pills.In 2010 Humana purchased Concentra Health Services, an unrelated company in Texas that manages medical centers in several states. As a result, Humana officials say they've received angry responses from people who haven’t made the distinction.Humana is now asking the courts to consider an injunction.Humana tried to stop the Preval Group from Portland, Maine from marketing the Concentra name last year. The company ran ads in Texas, which Humana says confuses consumers. But the Preval Group counsel said they’ll consider re-branding the name when its pill inventory is scheduled to run out in April.