 <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]  by your pharmacist before you start taking lanthanum and each time you get a refill. If you have any questions, ask your doctor or pharmacist. Take this medication by mouth as directed by your doctor, usually with or right after meals. Sprinkle the powder on a small amount of applesauce or soft food and swallow the mixture right away. Do not open the powder packet until you are ready to use it. Do not store the drug/food mixture for future use. Lanthanum powder will not dissolve in liquid. 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 Fosrenol 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 </s>