Family Life What is the most intense pain killer? What is the most intense pain killer? Opioids more powerful than morphine include hydromorphone (Dilaudid) and oxymorphone (Opana). But the strongest opioid in community use is fentanyl which, in its intravenous form, is 70 to 100 times more potent than morphine. Related Posts:Does Suboxone also help with pain?Can an ER doctor prescribe pain meds?What is the half-life for morphine?What is naltrexone hydrochloride prescribed for?