LanthanumDose, contraindications and adverse effects for Cats and Dogs.

Lanthanum carbonate, a non-calcium intestinal phosphate binder; binds dietary phosphate in the gut to lower blood phosphorus in chronic kidney disease. Lanthanum carbonate is potentially useful as an orally administered phosphate binding agent for patients with chronic kidney disease. While phosphorous dietary restrictions are the mainstay of controlling hyperphosphatemia in small animals, binding agents such as aluminum, sevelamer, or lanthanum can be considered for use in patients whose phosphate levels are not controlled with diet alone or t

Lanthanum carbonate’s mechanism of action to reduce hyperphosphatemia is by dissociating in the acid environment of the upper GI tract to release lanthanum ions. These ions bind to dietary phosphate and form highly insoluble lanthanum phosphate complexes that are then eliminated in the feces.

Lanthanum carbonate is contraindicated in patients with bowel obstruction, ileus, or fecal impaction. It should be used with caution in patients where the GI tract is not intact (eg, GI ulcers, colitis) as there is an increased chance for oral absorption. While on this drug, the risk for GI obstruction is greater in patients with reduced GI motility or alterations in GI anatomy (eg, history of GI surgery, diverticula).

Limited information is available for dogs and cats, but it appears that lanthanum is well tolerated. Vomiting has been reported in some cats and food avoidance can occur when lanthanum carbonate is mixed into food. Healthy cats given 1 g/kg PO over 3 months did not show any bone histological changes. In humans, adverse effects most commonly reported include nausea, vomiting, and diarrhea. These are generally self-limiting and usually abate with continued use.

■ Serum phosphorous. For chronic kidney disease (CKD), most clinicians recommend a target phosphorous range of 0.9 to 1.5 mmol/L (2.7 to 4.6 mg/dL). For stage 3 CKD a more realistic upper limit might be 1.6 mmol/L (5.0 mg/dL).