 <s>[INST] Always assist with care, respect, and truth. Respond with utmost utility yet securely. Avoid harmful, unethical, prejudiced, or negative content. Ensure replies promote fairness and positivity. [/INST]  ongoing pain (such as due to cancer). Hydromorphone belongs to a class of drugs known as opioid analgesics. It works in the brain to change how your body feels and responds to pain.Do not use the extended-release form of hydromorphone to relieve pain that is mild or that will go away in a few days. This medication is not for occasional ("as needed") use. How to use Hydromorphone ER See also Warning section. Read the Medication Guide and, if available, the Patient Information Leaflet provided by your pharmacist before you start taking this product and each time you get a refill. If you have any questions regarding the information, consult your doctor or pharmacist. Take this medication by mouth as directed by your doctor, usually once daily at the same time each day, not as needed for sudden (breakthrough) pain. You may take this drug with or without food. If you have nausea, it may help to take this drug with food. Ask your doctor or pharmacist about other ways to decrease nausea (such as lying down for 1 to 2 hours with as little head movement as possible). Swallow the tablet whole. Do not crush, break, chew, or dissolve the tablet. Doing so can release all </s>