 <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]  tablet by mouth with a glass of water as needed. To prevent heartburn, take 1 tablet by mouth with a glass of water right before or up to 30 minutes before eating food or drinking beverages that cause heartburn. Do not take more than 2 tablets in 24 hours unless directed by your doctor. Do not take for more than 14 days in a row without talking with your doctor. Inform your doctor if your symptoms do not improve or if they worsen.The side effects of Tagamet HB Oral: Headache, dizziness, drowsiness, or diarrhea may occur. If any of these effects last or get worse, tell your doctor or pharmacist promptly. If your doctor has directed you to use this medication, remember that 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: nausea/vomiting that doesn't stop, mental/mood changes (such as agitation, confusion, depression, hallucinations), trouble urinating, muscle/joint pain, breast swelling/soreness in males, decreased sexual ability (with very high doses of this medication), easy bruising/bleeding, </s>