To make sure Demerol is safe for you, tell your doctor if you have ever had:
any type of breathing problem or lung disease;
a blockage in your stomach or intestines;
a head injury, brain tumor, or seizures;
drug or alcohol addiction, or mental illness;
liver or kidney disease;
Get emergency medical help if you have signs of an allergic reaction to Demerol: hives; difficult breathing; swelling of your face, lips, tongue, or throat.
Like other opioid medicines, meperidine can slow your breathing. Death may occur if breathing becomes too weak. A person caring for you should seek emergency medical attention if you have slow breathing with long pauses, blue colored lips, or if you are hard to wake up.
Stop using Demerol and call your doctor at once if you have:
weak or shallow breathing, slow heartbeat;
severe drowsiness, feeling like you might pass out;
confusion, mood changes, agitation, hallucinations;
tremors, muscle movements you cannot control, or a seizure (convulsions);
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.
Meperidine is more likely to cause breathing problems in older adults and people who are severely ill, malnourished, or otherwise debilitated.