Bristol-Myers (BMY 1.30%)Johnson & Johnson (JNJ 1.49%), and Merck (MRK 0.44%), are among the most widely owned dividend paying drug companies and sales at all three are feeling the patent pinch.

With the patent cliff ready to erase $66 billion in industry sales next year and shares trading at lofty levels, should these three be in your dividend portfolio?

In the following slideshow, you'll find info on which patent losses are taking their toll, which products are driving sales higher, and whether dividend payouts could grow or shrink.