Dilaudid 8 mg is a pain relief medicine. It isDilaudid 8 mg is a potent opioid analgesic prescribed for moderate to severe pain relief, including postoperative discomfort and injury-related suffering. Each tablet contains 8 mg of hydromorphone, which binds to central nervous system opioid receptors to block pain signals and alter pain perception. Offering rapid onset and an effective duration, Dilaudid supports acute pain management. also named Hydromorphone hydrochloride. P d 8 pill is in a white triangular shape.