Neue eisenhaltige Phosphatbinder – Erweiterung des Behandlungsspektrums bei Nierenkranken

Sowohl Eisenzitrat als auch Sucroferric Oxyhdroxyd sind wirksame, sichere und verträgliche Phosphatbinder. Beide Substanzen sind den bislang verfügbaren Phosphatbindern nicht unterlegen und erweitern somit in positiver Weise die Therapiemöglichkeiten der Hyperphosphatämie. Eisenzitrat wirkt zudem als orales Eisensupplement, da der Zitratanteil offenbar selbst bei fortgeschrittener Niereninsuffizienz eine signifikante intestinale Eisenaufnahme ermöglicht. Hier mag es sich um einen relevanten „Zusatznutzen“ handeln, insbesondere bei Patienten im unmittelbaren Prädialysestadium oder bei Peritonealdialysepatienten. Allerdings ist noch nicht abschließend geklärt, inwieweit bei langfristiger Einnahme eine unerwünschte Eisenakkumulation auszuschließen ist. Dazu muss parallel zur Behandlung mit Eisenzitrat zwingend auf die Vermeidung oraler Aluminiumzufuhr geachtet werden. Da bei Sucroferric Oxyhdroxyd das Eisen in einer Zucker-Stärke-Matrix gebunden ist, kommt es hier zu einer wesentlich geringeren intestinalen Eisenaufnahme, diese Substanz scheint im Endeffekt einen mehr oder weniger neutralen Effekt auf den Eisenstoffwechsel zu besitzen. Der größte „Zusatznutzen“ von Sucroferric Oxyhydroxyd liegt vermutlich bei einer hohen phosphatbindenden Effektivität im Kontext einer geringen Tablettenlast, was insbesondere die Therapieadhärenz positiv beeinflussen sollte.

Both ferric citrate and sucroferric oxyhydroxyde are effective, safe and well-tolerated phosphate binders. Both substances are non-inferior compared to available standard therapy and will thus broaden the armatorium of phosphate lowering treatment options. In addition, ferric citrate may serve as an effective oral iron supplementation, because citrate obviously facilitates intestinal iron uptake even in patients with advanced chronic kidney disease (CKD). This may be regarded as a relevant added value, especially in pre-ESRD stages and in patients on peritoneal dialysis. However, it will have to be excluded that ferric citrate leads to an excessive iron accumulation with long-term use. Further, in the presence of ferric citrate medication, parallel oral aluminum intake must be carefully avoided. In case of sucroferric oxyhydroxyde, the iron is bound in a sugar/starch matrix and thus significantly less available for intestinal absorption. In quintessence, the clinical impact of sucroferric oxyhydroxyde on iron metabolism seems almost neutral. A significant added value of sucroferric oxyhydroxyde is related to its high phosphate-binding capacity in the context of a low pill burden. This fact should positively impact on patient adherence to the treatment.

Key words

ferric citrate - sucroferric oxyhydroxyde - phosphate binders - chronic kidney disease - dialysis patients

• Literatur

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