Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent.

The side effects listed below are not experienced by everyone who takes Fosrenol (Lanthanum-carbonate). If you are concerned about side effects, discuss the risks and benefits of Fosrenol (Lanthanum-carbonate) with your doctor.

The following side effects have been reported by at least 1% of people taking Fosrenol (Lanthanum-carbonate). Many of these side effects can be managed, and some may go away on their own over time.

Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.

• abdominal cramps
• appetite changes
• constipation
• Diarrhea
• gas
• heartburn
• nausea
• taste changes
• tooth injury
• vomiting

Although most of the side effects listed below don't happen very often, they could lead to serious problems if you do not check with your doctor or seek medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

• allergic skin reaction (rashes, Hives, itching)
• chest pain
• Low Blood Pressure (dizziness or lightheadedness, especially when rising from a lying or sitting position)
• numbness, tingling, or muscle spasms (signs of low levels of calcium)
• swelling in your legs and arms

Stop taking the medication and seek immediate medical attention ifany of the following occur:

• chest pain
• signs of a blockage of the intestines (e.g., abdominal bloating, abdominal pain, swelling, cramps, constipation, vomiting)

Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking Fosrenol (Lanthanum-carbonate).

250 mg
Each white-to-off-white, round, flat chewable tablet with "S405" and "250" printed on one side contains 250 mg of elemental lanthanum (as lanthanum carbonate hydrate).Nonmedicinal ingredients: colloidal silicon dioxide, dextrates (hydrated), and magnesium stearate.

500 mg
Each white-to-off-white, round, flat chewable tablet with "S405" and "500" printed on one side contains 500 mg of elemental lanthanum (as lanthanum carbonate hydrate). Nonmedicinal ingredients: colloidal silicon dioxide, dextrates (hydrated), and magnesium stearate.

750 mg
Each white-to-off-white, round, flat chewable tablet with "S405" and "750" printed on one side contains 750 mg of elemental lanthanum (as lanthanum carbonate hydrate).Nonmedicinal ingredients: colloidal silicon dioxide, dextrates (hydrated), and magnesium stearate.

1,000 mg
Each white-to-off-white, round, flat chewable tablet with "S405" and "1000" printed on one side contains 1,000 mg of elemental lanthanum (as lanthanum carbonate hydrate). Nonmedicinal ingredients: colloidal silicon dioxide, dextrates (hydrated), and magnesium stearate.

Do not take Fosrenol (Lanthanum-carbonate) if you:

• are allergic to lanthanum or any ingredients of the medication
• have a bowel obstruction
• have severe Constipation
• have low blood phosphate levels (hypophosphatemia)

There may be an interaction between lanthanum and any of the following:

• ampicillin
• angiotensin-converting enzyme inhibitors (e.g., Lisinopril, perindopril, Ramipril)
• chloroquine
• hydroxychloroquine
• ketoconazole
• quinolone antibiotics (e.g., ciprofloxacin, levofloxacin, moxifloxacin)
• statins (e.g., Atorvastatin, Lovastatin, Simvastatin)
• Tetracycline antibiotics (e.g., doxycycline, Minocycline, tetracycline)
• Thyroid medications for an underactive thyroid (e.g., Levothyroxine)

If you are taking any of these medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:

• stop taking one of the medications,
• change one of the medications to another,
• change how you are taking one or both of the medications, or
• leave everything as is.

An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.

Medications other than those listed above may interact with Fosrenol (Lanthanum-carbonate). Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the Nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.

Before you begin taking a medication, be sure to inform your doctor of any medical conditions or Allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should take Fosrenol (Lanthanum-carbonate).

Bone conditions: Lanthanum has been shown to accumulate in body tissues and bones. There is limited information to conclude whether or not Fosrenol (Lanthanum-carbonate) affects bone quality beyond 2 years of therapy.

Liver disease: The safety and effectiveness of Fosrenol (Lanthanum-carbonate) have not been established for people with decreased liver function. If you have reduced liver function or liver disease, discuss with your doctor how Fosrenol (Lanthanum-carbonate) may affect your medical condition, how your medical condition may affect the dosing and effectiveness of Fosrenol (Lanthanum-carbonate), and whether any special monitoring is needed.

Stomach problems: Lanthanum may cause very serious bowel obstruction (i.e., blockage). To reduce the risk of bowel obstruction, chew the tablets completely. If you have a history of bowel obstruction, stomach surgery, decreased stomach motility, or constipation, make sure your doctor knows and has taken this into account before you start taking lanthanum. The safety and effectiveness of Fosrenol (Lanthanum-carbonate) have not been established for people with acute peptic ulcer, Ulcerative Colitis or Crohn's Disease. If you have these conditions, discuss with your doctor how Fosrenol (Lanthanum-carbonate) may affect your medical condition, how your medical condition may affect the dosing and effectiveness of Fosrenol (Lanthanum-carbonate), and whether any special monitoring is needed.

Pregnancy: The safety and effectiveness of Fosrenol (Lanthanum-carbonate) have not been established for pregnant women. Lanthanum is not recommended for use during pregnancy.

Breast-feeding: It is not known if lanthanum passes into breast milk. If you are a breast-feeding mother and are taking Fosrenol (Lanthanum-carbonate), it may affect your baby. Talk to your doctor about whether you should continue breast-feeding.

Children and adolescents: The safety and effectiveness of using Fosrenol (Lanthanum-carbonate) have not been established for children and adolescents under 18 years of age.