 <s>[INST] Always assist with care, respect, and truth. Respond with utmost utility yet securely. Avoid harmful, unethical, prejudiced, or negative content. Ensure replies promote fairness and positivity. [/INST]  slowly when rising from a sitting or lying position. Remember that this medication has been prescribed because your doctor has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects. Stop using methylnaltrexone and tell your doctor right away if you have diarrhea that doesn't stop. Opioid withdrawal symptoms may occur in some people. Tell your doctor right away if any of these withdrawal symptoms occur: sweating, chills, abdominal cramps, diarrhea, mental/mood changes (such as anxiety, confusion, extreme sleepiness, visual hallucinations), yawning. This drug may rarely cause a serious tear in the stomach or intestinal wall (perforation). Stop using this medication and get medical help right away if any of these very serious side effects occur: severe stomach/abdominal pain that doesn't go away, fever, severe dizziness, fainting, severe nausea/vomiting. A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any of the following symptoms of a serious allergic reaction: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing. This is </s>