Schering will be coming out with a second generation (Claritin) drug in the next few months, so it depends how many people they convert (to the new drug), ... They could be in Merck's shoes a few quarters from now, but I don't think they have the visibility to say.
The concern is that Bristol could be the next shoe to drop as far as patent expiration and reining in the numbers, ... But the company has a pretty decent late-stage pipeline.