Lanthanum carbonate
Pronunciation: LAN-tha-num KAR-boh-nate.
- Generic name
- lanthanum carbonate
- Brand names
- FOSRENOL
- Drug class
- Phosphate binder
- Form
- Chewable tablet or oral powder
- Route
- Oral
- Legal status
- Prescription-only medicine
Availability and supply rules vary by country
Trade names by country: United States · Canada
Australia: · Full directory
What lanthanum carbonate is and how it works
Lanthanum carbonate is a phosphate-binding medicine that reduces phosphate absorption from food in the gut. It is used to help control serum phosphate levels in people with end-stage renal disease, as part of a management plan that also typically includes dietary phosphate restriction and dialysis. (1)
The reviewed label describes lanthanum carbonate as one part of ESRD phosphate management, which usually also includes reduced dietary phosphate intake and dialysis. It is taken with or immediately after meals so it can bind phosphate from food. A clinician must decide the dose and monitor phosphate levels regularly.
Mechanism of action: how lanthanum carbonate works
Lanthanum carbonate is a phosphate binder that releases lanthanum ions in the acid environment of the stomach, binding dietary phosphate and forming insoluble lanthanum-phosphate complexes, thereby reducing intestinal phosphate absorption. It is radio-opaque and may appear as an imaging finding resembling a radiographic contrast agent on abdominal X-rays. (1)
What lanthanum carbonate is used for
Reduction of serum phosphate in end-stage renal disease
Lanthanum carbonate is indicated to reduce serum phosphate in patients with end-stage renal disease. It is used together with dietary phosphate restriction and dialysis. (1)
Before taking lanthanum carbonate
Do not take / not appropriate for
- Tell your prescriber if you have a known hypersensitivity to lanthanum carbonate or any of its ingredients. The label lists this as a contraindication; your prescriber will confirm whether this medicine is appropriate for you and, if you are already taking it, will advise on continuing or stopping. (all products) (1)
- Tell your prescriber if you have bowel obstruction, ileus, or faecal impaction. The label lists these as contraindications; your prescriber will confirm whether this medicine is appropriate for you and, if you are already taking it, will advise on continuing or stopping. (all products) (1)
Tell your clinician about
- Any history of gastrointestinal surgery, bowel perforation, obstruction, or hypomotility disorders that could increase the risk of serious gastrointestinal complications.
- All other medicines, vitamins, or supplements you take, including levothyroxine, quinolone antibiotics, calcium-, aluminium-, or magnesium-containing antacids, and any other oral drug that might have its absorption changed.
- If you are pregnant, planning pregnancy, or breastfeeding — non-lanthanum phosphate binders are generally recommended instead.
- Any problems chewing or swallowing, because the chewable tablet must be chewed completely.
- If you are scheduled for an abdominal X-ray, mention that you take lanthanum carbonate — the label notes it is radio-opaque and may appear on the image resembling a radiographic contrast agent.
How to take lanthanum carbonate
- Take lanthanum carbonate only as directed by your clinician and with or immediately after meals.
- The clinician will start with a total daily dose of 1,500 mg, divided across meals, and then adjust it every 2–3 weeks based on your serum phosphate levels.
- In studies, daily doses used across meals ranged from 375 mg to 3,000 mg; typical maintenance was 1,500–3,000 mg daily in divided doses.
- If using the chewable tablet, chew the tablet completely before swallowing. Do not swallow whole tablets, as this can increase the risk of serious gastrointestinal complications.
- Do not change the dose, number of tablets, or timing yourself.
Procedures and treatment changes
Tell the treating team before surgery, procedures, or any medicine change. Do not alter treatment without the responsible clinician. (1)
Missed dose
Gap — no missed-dose guidance was reviewed in this source pass. Contact your clinician for advice if you miss a dose.
Overdose
Gap — no specific overdose-management protocol was reviewed in this source pass. If you think you or someone else may have taken too much lanthanum carbonate, contact your clinician or poison-information service promptly. Seek emergency care for any severe or worsening symptoms. (1)
Side effects
The data below come primarily from controlled clinical trials in end-stage renal disease and post-approval reporting. Effects may vary.
Nausea
What to notice: Feeling sick, which occurred in about 11% of treated people versus 5% on placebo.
What to do: Tell the treatment team if nausea persists or makes it difficult to eat or to take the medicine as prescribed. (1)
Vomiting
What to notice: Being sick, reported in about 9% of treated people versus 4% on placebo.
What to do: Inform the prescribing team, particularly if vomiting occurs frequently and might affect the dose timing. (1)
Abdominal pain
What to notice: Pain in the stomach area, reported in about 5% of treated people versus 0% on placebo.
What to do: Contact the treatment team for assessment if pain is persistent, worsening, or severe. (1)
Signs of gastrointestinal obstruction or impaction
What to notice: Not established from the sources reviewed: a specific patient-facing symptom list was not established in the sources reviewed for this page beyond the named risks of gastrointestinal obstruction, perforation, and impaction.
What to do: Seek prompt medical assessment. Lanthanum carbonate has been associated with serious gastrointestinal obstruction, perforation, and impaction — especially in people with abnormal gut anatomy, hypomotility disorders, or if tablets are swallowed whole. (1)
Tooth injury while chewing the tablet
What to notice: Not established from the sources reviewed: specific patient-facing symptom detail was not established in the sources reviewed for this page beyond post-approval reports of "tooth injury while chewing tablets."
What to do: Report this to your clinician and dentist for evaluation. (1)
Allergic skin reaction
What to notice: Not established from the sources reviewed: specific patient-facing symptom detail was not established in the sources reviewed for this page beyond post-approval reports of "allergic skin reactions."
What to do: Contact the prescribing team for assessment. (1)
Serious warnings
Gastrointestinal obstruction, perforation, or impaction — emergency
Symptoms: Not established from the sources reviewed: a specific patient-facing symptom list was not established in the sources reviewed for this page beyond the named risks of gastrointestinal obstruction, perforation, and impaction.
Action: Seek emergency medical attention immediately. People with abnormal gastrointestinal anatomy, hypomotility disorders, or those taking tablets without chewing them completely are at higher risk. (1)
Interactions
| Medicine or test | Effect | Action |
|---|---|---|
| Antacids containing aluminium, magnesium, or calcium | The label recommends separating administration. | Separate dosing by at least 2 hours. (1) |
| Quinolone antibiotics | Lanthanum carbonate can bind quinolones in the gut, potentially reducing antibiotic absorption and effectiveness. | Take the antibiotic at least 1 hour before, or 4 hours after, lanthanum carbonate. (1) |
| Levothyroxine | Lanthanum carbonate can reduce absorption of levothyroxine. | Separate doses by at least 2 hours (before or after). Thyroid-function (TSH) monitoring is recommended when these medicines are used together. (1) |
| Other oral medicines | Lanthanum carbonate can bind many drugs taken by mouth, potentially decreasing their absorption. | Consider separating the timing; give the clinician and pharmacist a complete medicine list so they can advise on timing for each one. (1) |
Pregnancy, breastfeeding, kidney/liver function, age
Pregnancy and breastfeeding
Non-lanthanum phosphate binders are recommended instead during pregnancy and breastfeeding. Animal studies showed lanthanum deposition in developing fetal bone. Human data are insufficient. If you are pregnant, planning pregnancy, or breastfeeding, discuss management with your clinician before continuing this medicine. (1)
People with gastrointestinal disorders or abnormal anatomy
People with a history of gastrointestinal surgery, obstruction, hypomotility, ileus, or bowel perforation should discuss the increased gastrointestinal risk with their clinician. (1)
Children
Gap — the use of lanthanum carbonate in children with end-stage renal disease was not confirmed in the sources reviewed in this pass. (1)
Monitoring
Before starting
- General clinical practice considerations (not expressly specified as label monitoring requirements in the reviewed source): assess gastrointestinal history, including any abnormal anatomy, hypomotility disorder, or prior bowel obstruction or impaction; review all other oral medicines, supplements, and antacids for possible binding and timing separation; check pregnancy and breastfeeding status, since other phosphate binders are generally preferred during these periods; record baseline serum phosphate level.
During treatment
- Monitor serum phosphate every 2–3 weeks while the dose is being titrated, and regularly thereafter (exact maintenance interval not further specified).
- Adjust the daily dose, divided across meals, until acceptable serum phosphate is reached.
- Ask about gastrointestinal symptoms, chewing-related tooth problems, and any new allergic-type skin changes.
- Check for any new medicines that may require timing separation.
Storage
Gap — no storage instructions were reviewed in this source pass. Refer to the pharmacy label and the manufacturer’s product information.
Professional information
Clinician-facing context only. Use the current local product information and relevant guidelines for end-stage renal disease bone-mineral management.
United States
Indication: Reduction of serum phosphate in end-stage renal disease
Dose summary: Starting total daily dose is 1,500 mg, divided and taken with or immediately after meals. Titrate every 2–3 weeks according to serum phosphate. In studies, daily doses across meals ranged from 375 mg to 3,000 mg; typical maintenance was 1,500–3,000 mg daily. Tablets must be chewed completely; intact-tablet swallowing increases gastrointestinal risk.
Renal context: Use is specific to end-stage renal disease; dose is titrated to serum phosphate. (1)
Hepatic guidance
Gap — no hepatic impairment dosing guidance was reviewed in this source pass.
Frequently asked questions
Can I swallow the Fosrenol chewable tablet whole?
No. You must chew the tablet completely before swallowing. Swallowing tablets whole increases the risk of serious gastrointestinal complications such as obstruction or perforation. (1)
Why do I need to separate my other medicines from lanthanum carbonate?
Lanthanum carbonate can bind many oral medicines in the gut, which may reduce how much of the other medicine your body absorbs. The timing needed differs by medicine — your clinician or pharmacist can advise on the right separation for each one. (1)
Is lanthanum carbonate safe during pregnancy?
Non-lanthanum phosphate binders are recommended instead during pregnancy. If you are pregnant or planning pregnancy, speak to your clinician before starting or continuing this medicine. (1)
What is the mechanism of action of lanthanum carbonate?
Lanthanum carbonate is a phosphate binder that releases lanthanum ions in the acid environment of the stomach, binding dietary phosphate and forming insoluble lanthanum-phosphate complexes, thereby reducing intestinal phosphate absorption. It is radio-opaque and may appear as an imaging finding resembling a radiographic contrast agent on abdominal X-rays. (1)
What is the generic name of Lanthanum carbonate?
The generic name is lanthanum carbonate. It is sold under brand names including FOSRENOL. (1)
What class of drug is lanthanum carbonate?
Lanthanum carbonate is classed as: Phosphate binder. (1)
References
- FOSRENOL (lanthanum carbonate) chewable tablets / oral powder — prescribing informationU.S. Food and Drug Administration · United States · dated 2026 · accessed 2026-08-05 · source 1
- LANTHANUM CARBONATE POWDER [AX PHARMACEUTICAL CORP] — US prescribing information (DailyMed SPL)U.S. National Library of Medicine (DailyMed) · US · accessed 2026-08-14 · source 2
- Lanthanum — patient drug information (MedlinePlus)U.S. National Library of Medicine (MedlinePlus) · US · accessed 2026-08-14 · source 3
- Lanthanum carbonate — FDA approval record (Drugs@FDA ANDA206868)U.S. Food and Drug Administration · US · accessed 2026-08-14 · source 4
- lanthanum carbonate — RxNorm normalized drug concept (RXCUI 234416)U.S. National Library of Medicine (RxNorm) · US · accessed 2026-08-14 · source 5
Brand names by country
Single-ingredient lanthanum carbonate names are shown separately by country. Product availability, strengths, and supply rules can change; combination products are not included here.
Priority countries
United States
- Lanthanum Metallicum500 [hp_C], 6 [hp_C], 30 [hp_C], 1 [hp_M], 12 [hp_C], 100 [hp_C], 1 [hp_Q], 200 [hp_C] · hahnemann laboratories, inc.
- Fosrenol500 mg, 1000 mg, 750 mg · takeda pharmaceuticals america, inc.
Canada
- FOSRENOL