The Food and Drug Administration has been cracking down on a class of constipation drugs because of fears around potential cardiovascular risks. This additional regulatory oversight has big implications for a drug still in the pipeline from Nektar Therapeutics (NASDAQ:NKTR), and it brought the company's shares down 14% on Monday. In this video, Motley Fool health care analyst Brenton Flynn talks about the market for these drugs, and how the FDA's concerns are impacting not only Nektar but several other companies operating in this space.