Lanthanum Carbonate

Approved Indications:

• Hyperphosphatemia in End-Stage Renal Disease (ESRD):
  Lanthanum carbonate is indicated to reduce elevated serum phosphate levels in adult patients with ESRD who are undergoing hemodialysis or peritoneal dialysis. It is used when dietary phosphate restriction alone is insufficient.

Clinically Accepted Off-Label Use:

• Hyperphosphatemia in Non-Dialysis Chronic Kidney Disease (CKD) Stages 3–5:
  Although not FDA-approved for non-dialysis CKD patients, lanthanum carbonate is occasionally used off-label to manage persistent hyperphosphatemia when calcium-based or aluminum-based binders are inappropriate or poorly tolerated.

Route of Administration: Oral
Formulations: Chewable tablets and oral powder for suspension
Dosing Frequency: Three times daily with meals

Adults (≥18 years):

• Initial Dose: 500 mg orally with each meal (total 1,500 mg/day)
• Titration: Dose may be increased in 750 mg/day increments every 2–3 weeks based on serum phosphate levels
• Maintenance Dose: Typically 1,500–3,000 mg/day
• Maximum Dose: 4,500 mg/day

Pediatrics (<18 years):

• Safety and efficacy in pediatric patients have not been established. Use is not recommended.

Elderly (≥65 years):

• No specific dose adjustment required. Monitor for gastrointestinal tolerance.

Renal Impairment:

• No dose adjustment needed. Lanthanum carbonate is specifically intended for patients with advanced renal disease.

Hepatic Impairment:

• No dosage adjustment is required due to minimal systemic absorption.

Administration Instructions:

• Chewable tablets must be thoroughly chewed before swallowing. Do not swallow whole.
• The oral powder may be sprinkled onto a small quantity of soft food and consumed immediately. Do not mix in liquid.

Lanthanum carbonate works as a phosphate binder. In the acidic environment of the stomach, it dissociates into lanthanum ions (La³⁺), which bind dietary phosphate in the gastrointestinal tract to form insoluble lanthanum phosphate complexes. These complexes are excreted in the feces, thereby reducing the absorption of phosphate into the bloodstream. As a result, serum phosphate levels are lowered. This action is local within the GI tract and does not depend on systemic absorption.

• Absorption: Negligible systemic absorption (<0.002%)
• Distribution: Minimal; very low plasma concentrations due to poor absorption
• Metabolism: Not metabolized
• Excretion: Primarily excreted in feces as insoluble complexes
• Half-life: Not clinically relevant due to negligible systemic levels
• Onset of Action: Serum phosphate reduction typically seen within a few days of therapy
• Bioavailability: Very low; therapeutic effect is due to local GI action

Pregnancy:

• FDA Category: Not assigned (previously Category C)
• Summary: Animal studies have shown fetal skeletal abnormalities at high doses. There are no adequate and well-controlled studies in pregnant women. Use only if the potential benefit justifies the potential risk.

Lactation:

• It is not known whether lanthanum is excreted in human milk. Given its minimal systemic absorption, significant infant exposure is unlikely. However, caution is advised. Consider discontinuing breastfeeding or the drug based on clinical need.

• Primary Class: Phosphate Binder
• Subclass: Non-calcium, non-aluminum phosphate binder

• Known hypersensitivity to lanthanum carbonate or any component of the formulation
• Bowel obstruction, ileus, or fecal impaction
• Hypophosphatemia

• Gastrointestinal Disorders: Use with caution in patients with active peptic ulcers, ulcerative colitis, Crohn’s disease, or history of bowel surgery or obstruction.
• Radiopaque Effects: Lanthanum may appear as a dense object on abdominal X-rays and could be misinterpreted as a foreign body.
• Fecal Impaction/Obstruction Risk: Especially in elderly patients or those with impaired bowel motility. Ensure tablets are thoroughly chewed.
• Monitoring: Regular serum phosphate monitoring is required to adjust the dose and avoid hypophosphatemia.
• Administration Precautions: Inadequate chewing may increase the risk of GI complications.

Common Adverse Effects (mostly gastrointestinal):

• Nausea
• Vomiting
• Diarrhea
• Constipation
• Abdominal discomfort
• Flatulence

Less Common or Serious Effects:

• Intestinal obstruction or ileus
• Fecal impaction
• Gastrointestinal perforation (rare)

Rare Effects:

• Hypersensitivity reactions (rash, pruritus)
• Myalgia
• Dental injuries (if tablets are not chewed properly)

Onset & Severity:

• Gastrointestinal side effects generally occur early in therapy and are typically mild to moderate. Most are dose-related and reversible upon discontinuation or dose adjustment.

Drug-Drug Interactions:

• Quinolone Antibiotics (e.g., ciprofloxacin): Reduced absorption. Administer quinolones at least 1 hour before or 4 hours after lanthanum.
• Levothyroxine: Binding may reduce absorption. Separate administration and monitor thyroid function.
• Tetracyclines: Reduced bioavailability due to chelation.
• Iron, Zinc, Fat-Soluble Vitamins: May interfere with absorption. Supplement as needed.

Enzyme Interactions:

• No significant interaction with CYP450 enzyme systems due to minimal systemic absorption.

• KDIGO 2024 Guidelines: Recommend non-calcium-based phosphate binders, including lanthanum carbonate, to minimize the risk of vascular calcification in patients with CKD and hyperphosphatemia.
• No major updates in FDA indications, black box warnings, or regulatory restrictions as of the latest review in 2024.

• Temperature: Store below 30°C (86°F)
• Humidity: Store in a dry place; protect from moisture
• Light Protection: Not required
• Special Handling:
• Keep chewable tablets in the original packaging to prevent moisture exposure
• Do not refrigerate
• Oral powder must be used immediately after mixing; do not store the reconstituted mixture