Lanthanum Carbonate
Lanthanum carbonate is an orally administered phosphate-binding agent primarily used to manage hyperphosphatemia in patients with end-stage renal disease (ESRD). While dietary phosphorus restriction remains the cornerstone of managing chronic kidney disease (CKD), phosphate binders are indicated when diet alone is insufficient or refused by the patient. > **Clinical Pearl:** Unlike calcium-based binders (which can cause hypercalcemia) or aluminum-based binders (which carry a risk of aluminum toxicity with long-term use), lanthanum is a non-calcium, non-aluminum binder, making it an attractive option for chronic management of hyperphosphatemia in veterinary patients.
Mechanism: Lanthanum carbonate acts locally in the gastrointestinal tract. * It dissociates in the acidic environment of the upper GI tract (stomach) to release **lanthanum ions (La³⁺)**. * These ions bind to dietary phosphate → forming highly insoluble **lanthanum phosphate complexes**. * These complexes cannot cross the intestinal mucosa and are subsequently eliminated in the feces, thereby reducing net intestinal absorption of phosphorus.
Dosing by species
- Phosphate binder · 200 mg (total dose) PO (on/in food) 2-3 times daily. · PO · 2-3 times daily · Anecdotally appears safe and effective.
- Phosphate binder (using Renalzin) · 2 mLs (400 mg) applied in the cat's food, once or twice daily depending on the cat's feeding regimen. · PO · once or twice daily
- Chronic kidney disease (Hyperphosphataemia) · 400-800 mg/cat/day · PO · divided according to feeding schedule (give some with every meal) · Chronic · Recommended starting dose is 400 mg per day. It is important to give some with every meal.
- Chronic kidney disease (Hyperphosphataemia) · 100 mg/kg/day · PO · divided between meals · Chronic · Dose adjustments should be based on serum phosphate levels monitored at 4-6 week intervals.
Doses are a clinical reference for licensed veterinary professionals. Always confirm against the current label and the individual patient.
Routes of administration
Contraindications
- Patients with non-intact GI tract (e.g., GI ulcers, colitis) - use with caution due to increased risk of systemic absorption
- Acute renal crisis (patients should be stabilized first)
Adverse effects
- Vomiting
- Nausea
- Inappetence
- None known according to the monograph
- Gastrointestinal upset (nausea, vomiting, diarrhea, or constipation) may occur (Clinical Pearl)
Drug interactions
- Allopurinol · Potential decreased absorption; separate dosing by 2 hours
- Chloroquine · Potential decreased absorption; separate dosing by 2 hours
- Corticosteroids · Potential decreased absorption; separate dosing by 2 hours
- Digoxin · Potential decreased absorption; separate dosing by 2 hours
- Ethambutol · Potential decreased absorption; separate dosing by 2 hours
- Fluoroquinolones · Potential decreased absorption; separate dosing by 2 hours
- H-2 Antagonists (ranitidine, famotidine) · Potential decreased absorption; separate dosing by 2 hours
- Iron Salts · Potential decreased absorption; separate dosing by 2 hours
- Isoniazid · Potential decreased absorption; separate dosing by 2 hours
- Penicillamine · Potential decreased absorption; separate dosing by 2 hours
- Phenothiazines · Potential decreased absorption; separate dosing by 2 hours
- Tetracyclines · Potential decreased absorption; separate dosing by 2 hours
- Thyroid Hormones · Potential decreased absorption; separate dosing by 2 hours
Monitoring
- Serum phosphorous
- Serum potassium
- Serum calcium
- Serum bicarbonate
- Serum chloride
- Serum phosphate levels (at 4-6 week intervals to adjust dosage and achieve target concentrations)
- Renal parameters (BUN, Creatinine, SDMA)
- Serum calcium levels
Overdose
No specific information located, but acute overdose is likely tolerated with potential for GI effects. Only supportive treatment should be required. In cats, oral dosages up to 1 gram/kg were tolerated, but repeated vomiting occurred at 2 grams/kg.
VetSheet drug reference is intended for licensed veterinary professionals as a clinical decision-support aid, not a substitute for professional judgement or the manufacturer’s current label.