 <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]  usually with or right after meals. Chew the tablets completely before swallowing to reduce the risk of stomach/abdominal side effects. You may crush the tablets to make it easier to chew them. Do not swallow the tablets whole. You do not need to swallow this medication with water. Take this medication regularly to get the most benefit from it. The dosage is based on your medical condition, response to treatment, and laboratory test results. Lanthanum may stop some medications from working well if you take them at the same time. Ask your pharmacist if you need to separate the time that you take your other medications from the time that you take lanthanum. See also Drug Interactions section.The side effects of Lanthanum Oral: Nausea, vomiting, stomach pain, diarrhea, or constipation 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: mental/mood changes, unusual muscle weakness/spasms, seizures. Rarely </s>