Lanthanum Orifarm (Lanthanum)

Lanthanum Orifarm is used as a phosphate binder to manage elevated serum phosphate levels in chronic kidney disease.

• Hyperphosphatemia in dialysis patients: lowers serum phosphate by binding dietary phosphate in the gut.
• Chronic kidney disease not yet on dialysis with high phosphate: reduces phosphate absorption to maintain target levels.
• End‑stage renal disease awaiting transplantation: assists in phosphate control while patients await transplant.

• Lanthanum Orifarm releases lanthanum ions in the gastrointestinal tract where they bind dietary phosphate, forming insoluble lanthanum‑phosphate complexes. These complexes are not absorbed and are eliminated in the feces, thereby decreasing the amount of phosphate that enters the systemic circulation and helping to maintain serum phosphate within the desired range.

Lanthanum Orifarm may cause gastrointestinal and systemic adverse reactions, which are categorized by frequency and severity.

Common Side Effects

• Nausea: mild to moderate discomfort in the stomach.
• Constipation: reduced bowel movements, sometimes requiring dietary adjustment.
• Abdominal pain: cramping or discomfort in the abdomen.
• Diarrhea: loose stools that may be transient.

Serious or Rare Side Effects

• Severe constipation or intestinal obstruction: may require medical evaluation.
• Hepatic enzyme elevation: abnormal liver function tests observed in rare cases.
• Allergic reactions: rash, itching, or swelling indicating hypersensitivity.

Before prescribing Lanthanum Orifarm, clinicians should consider several safety measures.

• Monitor serum phosphate: adjust dose to keep levels within target range.
• Assess gastrointestinal history: avoid in patients with severe constipation or known bowel obstruction.
• Check liver function: periodic testing is advised due to rare hepatic effects.
• Avoid concomitant use with other phosphate binders unless directed: may reduce efficacy.
• Store below 25°C: keep in the original pack, protect from moisture.

Lanthanum Orifarm can interact with other medications, affecting absorption or efficacy.

Major Interactions (Avoid)

• Other phosphate binders: concurrent use may diminish binding capacity.
• Aluminum or magnesium antacids: can compete for phosphate binding sites.
• High‑dose iron supplements: may reduce lanthanum binding efficiency.
• Tetracycline antibiotics: lanthanum may decrease antibiotic absorption.
• Sevelamer: combined use may lead to excessive phosphate binding.

Moderate Interactions (Monitor Closely)

• Vitamin D analogues: may increase calcium absorption, requiring monitoring.
• Calcium supplements: combined effect on mineral balance should be observed.
• Bisphosphonates: potential alteration in gastrointestinal absorption.
• Levothyroxine: monitor thyroid levels as absorption may be affected.
• Proton pump inhibitors: may change gastric pH, influencing lanthanum solubility.