Wyeth and Walgreen are locked in a legal battle over the drugstore chain’s move to sell a generic version of the Alavert allergy med that it markets as ‘Wal-Vert,’ The Daily Herald reports. What do you think? Does the packaging look similar or is our eyesight acting up again?

The retailer filed a lawsuit claiming the drugmaker wrongfully blocked a federal trademark application for its generic version and seeks a court order overturning an August decision by US patent officials, who denied its application. Walgreen filed the application in 2004 and is already selling the drug in stores and on its Web site. The trademark was initially approved in 2005.

Consumers immediately understand that the Wal-prefix indicates the product is a lower price alternative originating from Walgreens,” the Deerfield-based company said in the complaint filed Oct. 6 in Chicago federal court.

Interestingly, Walgreen also sells Wal-Dryl and Wal-itin, generic versions of Johnson & Johnson’s Benadryl and Schering-Plough’s Claritin, but Walgreen’s trademark applications for those generics weren’t challenged. (For some background, check out TTABlog).