The Trademark Trial and Appeal Board recently found that Walgreens' trademark WAL-ZYR, used for its generic version of Zyrtec (the allergy medication), is likely to be confused with the ZYRTEC mark by consumers in the marketplace. The TTAB therefore sustained an opposition to Walgreens' attempt to register WAL-ZYR.
This is a curious decision in that there's frankly no real likelihood than any real consumer would actually be confused by Walgreens' use of the WAL-ZYR mark. Anyone who has ever perused the aisles at a pharmacy knows that there are brand name medications, and there are generics. The generics are usually named something similar to the brand name medication, so you can easily identify them. At Walgreens, for instance, most of the store-brand generics start with "WAL-" and end with an homage to the brand name equivalent: Wal-Dryl (Benedryl), Wal-Zan (Zantac), Wal-Tussin (Robitussin), Wal-Sporin (Neosporin), Wal-Phed (Sudafed), Wal-Mucil (Metamucil), etc... These marks are not confusing. They are the opposite of confusing: they are illuminating.
I suspect Walgreens will appeal this decision to federal court, and I expect they will prevail.