Patients who are addicted to opioids — whether these drugs are legally filled prescriptions such as oxycodone or morphine or illegally acquired street drugs like heroin — may be unable to manage withdrawal symptoms alone without taking more of their opioids, reinforcing the addiction. If the patient is dealing with opioid substance abuse, stopping the drug abruptly may trigger a cascade of severe, and at times life-threatening, withdrawal symptoms that can include the following: Muscle pain Mood swings, anxiety, or depression Insomnia Nausea, vomiting, or diarrhea Heart palpitations Dilated pupils Blood pressure abnormalities