Get emergency medical help if you have signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.
Opioid medicine can slow or stop your breathing, and death may occur. A person caring for you should give naloxone and/or seek emergency medical attention if you have slow breathing with long pauses, blue colored lips, or if you are hard to wake up.
Call your doctor at once if you have:
weak or shallow breathing, breathing that stops;
a light-headed feeling, like you might pass out;
seizure (convulsions);
chest pain, wheezing, cough with yellow or green mucus;
severe vomiting;
high levels of serotonin in the body--agitation, hallucinations, fever, sweating, shivering, fast heart rate, muscle stiffness, twitching, loss of coordination, nausea, vomiting, diarrhea; or
low cortisol levels--nausea, vomiting, loss of appetite, dizziness, worsening tiredness or weakness.
Serious side effects may be more likely in older adults and those who are overweight, malnourished, or debilitated.
Common side effects may include:
dizziness, drowsiness;
headache, tiredness; or
stomach pain, nausea, vomiting, constipation.
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.
 Oxymorphone side effects (more detail)
