hydromorphone hydrochloride /-môr′fōn/ , an opioid analgesic. ▪ INDICATIONS: It is used to treat moderate to severe pain. ▪ CONTRAINDICATIONS: It is used with caution in many conditions, including head injuries, asthma, impaired renal or hepatic function, or unstable cardiovascular status. Known hypersensitivity to this drug prohibits its use. ▪ ADVERSE EFFECTS: Among the most serious adverse effects are drowsiness, dizziness, nausea, constipation, respiratory and circulatory depression, and drug addiction.