 <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]  your doctor if your condition lasts or gets worse.The side effects of Famotidine Intravenous: Headache, constipation, diarrhea, or pain/redness at the injection site may occur. If any of these effects last or get worse, tell your doctor or pharmacist promptly. 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. Tell your doctor right away if you have any serious side effects, including: easy bruising/bleeding, signs of infection (such as sore throat that doesn't go away, fever, chills), mental/mood changes (such as restlessness, confusion, depression), hearing/seeing things that are not there (hallucinations). Get medical help right away if you have any very serious side effects, including: fast/slow/irregular heartbeat, severe dizziness, fainting, seizure. A very serious allergic reaction to this drug is unlikely, but get medical help right away if it occurs. Symptoms of a serious allergic reaction may include: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing </s>