Merck (NYSE:MRK), 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.

David Williamson owns shares of Pfizer. Max Macaluso, Ph.D., and The Motley Fool have no positions in the stocks mentioned above. Try any of our Foolish newsletter services free for 30 days. We Fools don't all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.