Hydromorphone (Dilaudid®) is a painkiller in the opioid family, as is morphine. Hydromorphone is chemically related to morphine, and very commonly used for moderate to severe pain.

Often people are switched from morphine to hydromorphone to treat possible side effects from ongoing use of morphine, such as confusion or uncontrolled jerking movements. All opioids, including hydromorphone, can cause these side effects, but it takes a while for them to develop. Switching opioids allows the body to clear out the previous medication.

Hydromorphone may also be used instead of morphine if the kidneys aren’t functioning well or if someone is in kidney failure.

Technically hydromorphone is stronger than morphine. This simply means that a smaller quantity of hydromorphone has the same pain relieving effect as a larger quantity of morphine. It doesn’t mean it’s a better painkiller or has stronger side effects. The amount given is suited to the pain. The specific number of milligrams is not meaningful as long as pain is controlled. As with morphine, there’s no specific dose that is "a lot" or "too much." It all depends on the pain relief.