Efficacy, acceptability and tolerability of the new oral phosphate binder Lenziaren® in healthy cats fed a standard diet.

BACKGROUND: The efficacy, acceptability and tolerability of the new oral phosphate binder Lenziaren® (SBR759) were evaluated in a randomized parallel-group design study in 36 healthy cats (n = 6 per group). Five groups were fed once daily with a commercial diet containing 0.2% phosphorus ("standard diet") into which was mixed Lenziaren® at 0.25, 0.5, 1.0 or 2.0 g/day or no treatment (control group) daily for 30 days. A sixth group was fed a commercial diet containing lower amounts (0.12%) of phosphorus ("renal diet") and no treatment. RESULTS: When compared to the control group, Lenziaren® produced significant dose-related reductions in urine phosphate concentrations, urine phosphate excretion and fractional urinary phosphate excretion. Significant effects versus the control group were observed at the 0.5, 1.0 and 2.0 g/day dosages. Lenziaren® was well tolerated and was associated with higher food consumption and serum iron concentrations versus the control. When compared to the control group, the renal diet was associated with significantly lower urine phosphate concentrations and loss of body weight. Lenziaren® had similar effects on urine phosphate concentrations compared to the renal diet, but was not associated with loss of body weight. CONCLUSIONS: Lenziaren® was effective as an oral phosphate binder in cats fed with a standard diet containing 0.2% phosphorus. The acceptability and tolerability were good. Dosages of 0.5-1.0 g/cat per day are recommended for clinical testing in cats fed with a standard diet.

Tolerability and efficacy of the intestinal phosphate binder Lantharenol® in cats.

BACKGROUND: Tolerability and efficacy of the intestinal phosphate binder Lantharenol® (lanthanum carbonate octahydrate) were tested in two prospective, randomized and negative controlled laboratory studies with healthy adult cats fed commercial maintenance diets non-restricted in phosphorus. In the first study, the maximal tolerated dose was determined. Starting from a dose of 0.125 g/kg body weight mixed with the daily feed ration, the dose of Lantharenol® was doubled every other week until signs of intolerability were observed (N=10 cats compared to 5 untreated controls). In the second study, the effects of feed supplementation for two weeks with approximately 2, 6, and 20% of the maximal tolerated dose on phosphorus excretion patterns and balance were assessed (N=8 cats per group). RESULTS: Lantharenol® was found to be safe and well tolerated up to the dose of 1 g/kg bodyweight, corresponding to a concentration of 84 g Lantharenol®/kg complete feed, defined as dry matter with a standard moisture content of 12%. Feed supplementation for two weeks with approximately 2-20% of this dosage (i.e., 1.6, 4.8, and 16 g/kg complete feed) resulted in a shift from urinary to faecal phosphorus excretion. Apparent phosphorus digestibility was dose-dependently reduced compared to the control group fed with diet only (N=8). CONCLUSIONS: The feed additive was well accepted and tolerated by all cats. Therefore, Lantharenol® presents a well tolerated and efficacious option to individually tailor restriction of dietary phosphorus as indicated, for instance, in feline chronic kidney disease.