Bristol-Myers Squibb (NYSE:BMY) has had anything but a good ride in the wake of the patent cliff. The patent expiration of the company's former top-selling drug, Plavix, has obliterated the drug's sales in 2013 and taken a hammer to Bristol's top and bottom lines. Other top-selling drugs haven't been able to cover up Plavix's holes, but Bristol's stock hasn't suffered so far: Shares in this big pharma leader are up more than 28% year-to-date.

However, Bristol's falling income is making its 3.3% dividend look vulnerable. The company has raised its dividend every year since 2010, but will that continue now that Bristol's staring down the barrel of patent losses and falling revenue?

In the video below, Fool contributor Dan Carroll tells you what you need to know about Bristol's dividend and whether income investors should place their faith in this pharmaceutical giant that's adapting to life with the patent cliff.