Get emergency medical help if you have any signs of an allergic reaction to Dilaudid: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.
Like other narcotic medicines, hydromorphone can slow your breathing. Death may occur if breathing becomes too weak.
Call your doctor at once if you have:
noisy breathing, sighing, shallow breathing, breathing that stops during sleep;
confusion, feelings of extreme happiness or sadness;
severe weakness or drowsiness;
a light-headed feeling, like you might pass out;
infertility, missed menstrual periods;
impotence, sexual problems, loss of interest in sex; or
low cortisol levels - nausea, vomiting, loss of appetite, dizziness, worsening tiredness or weakness.
Seek medical attention right away if you have symptoms of serotonin syndrome, such as: agitation, hallucinations, fever, sweating, shivering, fast heart rate, muscle stiffness, twitching, loss of coordination, nausea, vomiting, or diarrhea.
Hydromorphone is more likely to cause breathing problems in older adults and people who are severely ill, malnourished, or otherwise debilitated.
Common Dilaudid side effects may include:
constipation, nausea, vomiting, stomach pain;
dizziness, drowsiness;
headache, tired feeling;
feelings of extreme happiness or sadness;
sweating, mild itching;
dry mouth; or
flushing (warmth, redness, or tingly feeling).
This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.
 Dilaudid side effects (more detail)
