The Food and Drug Administration's approval of immediate-release Abstral (fentanyl) transmucosal tablets provides a new option for managing breakthrough pain for adults with cancer.  Approved on Jan. 7, the drug is indicated for the management of breakthrough pain in patients aged 18 years and older with cancer, who already use around-the-clock opioid pain medication and who need and are able to safely use high doses of an additional opioid medicine.  Breakthrough pain is defined as pain that comes...