Merck (MRK -2.69%), a well-known dividend stock and longtime Dow component, is of interest to many investors throughout the world. However, as with any investment, there are compelling reasons to both buy and sell this stock.

In the following video, health-care analysts Max Macaluso and David Williamson take a close look at both sides of the coin and debate the importance of Merck's losing patent protection for its leading asthma drug, Singulair.