Despite suffering severe pain, about one in three older cancer patients do not end up taking opioids, the most potent of analgesics, according to a new study from Canada. It's not clear why these patients are not getting their pain treated with opioids, which include morphine, oxycodone and fentanyl. It could be that physicians are not prescribing the medications or that patients are getting prescriptions, but not filling them. They don't have … full story