Let's take a minute to talk about your medication. This medicine treats low levels of phosphorus in the body. Phosphorus is an important mineral that normally comes from food. You need healthy levels of phosphorus in your body for energy, and for your bones, teeth, muscles, and more. This medicine is often taken with breakfast, lunch, dinner and at bedtime. You should take this medicine exactly as directed by your doctor. Be sure to drink a full glass of water with each dose. Most people tolerate this medicine well. Some patients have stomach upset or diarrhea for the first few days. These are normal effects if they are mild, and should go away. It may also cause patients who have old kidney stones to pass them. If these or other effects become reasons you want to stop taking this medicine, please talk to your doctor or pharmacist. As with any medicine, rare side effects could occur. With a phosphorus supplement, these include swelling, thirst, weakness, numbness or tingling. They could also include shortness of breath, muscle cramps or dizziness. You should let your doctor know if you have these or other unusual changes to your body. To help keep this medicine safe for you, your doctor will follow you closely and will order blood tests. You should check with your doctor or pharmacist before taking other medicines, even if they do not require a prescription. You should not take certain antacids with this medicine. For best results, work closely with your health care team to understand your phosphorus needs.