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Editorial
Phosphate binders in patients
with chronic kidney disease: Between
the new and the old.
Dr Samia Ait Faqih
Impaired phosphate excretion by the kidney leads to Hyperphosphatemia. It is an independent predictor of cardiovascular disease and mortality
in patients with advanced
chronic kidney disease
(stage 4 and 5) particularly in case of dialysis.
Phosphate retention develops early in chronic kidney
disease (CKD) due to the reduction
in the filtered
phosphate load. Overt hyperphosphatemia develops when the estimated glomerular filtration rate (eGFR)
falls below 25 to 40 mL/min/1.73 m2.
Hyperphosphatemia is typically managed with oral phosphate
binders in conjunction with dietary phosphate
restriction. These drugs aim to decrease
serum phosphate by binding ingested phosphorus in the gastrointestinal tract and its transformation to non-absorbable complexes [1].
Phosphorus binders:
Three main types of phosphate
binder are available:
*Calcium-containing binders: calcium carbonate and calcium acetate are the most commonly
used drugs. The main advantage
of calcium binders
is the low cost for equivalent efficiency. However, hypercalcemia and accelerated vascular calcification are the main concerns with calcium-containing phosphate binders, particularly when they are combined
with vitamin
D therapy.
*Aluminium-based binders are a second-line drug in non- dialysis chronic
kidney disease. Their phosphate binding capacity is excellent. However, the aluminium accumulation toxicity
limits the long term use.
*Non-calcium-based binders (sevelamer®; lanthanum®; sucroferric oxyhydroxide; and Ferric
citrate) would
not increase calcium level but this type is only available for dialysis patients. These binders are equally
effective but may have relevant
side effects, including gastrointestinal symptoms
for sevelamer ® and risk of tissue accumulation for lanthanum®. Non calcium based binders
are considerably more expensive
[2].
Available phosphate binders are all effective in the treatment
of hyperphosphatemia. According
to some recent reviews, the calcium-free binders may limit the progression of vascular
calcifications compared others binders [3].
How to choose?
Many studies and meta-analysis shows that there is no convincing evidence
for improvements in cardiovascular mortality or fracture
risk between calcium
and calcium free binders
[4]. How can we strongly
justify the use of the new binders
without evidence?
The choice of phosphorus binders should be based on serum calcium level, drugs side effects and cost. KDIGO recommends to maintain the serum phosphate in the normal range and to restrict
the use of calcium
binders in the presence
of hypercalcemia, arterial calcification, bone disease
or serum parathyroid hormone (PTH) concentrations less than two times the upper
limit of the reference level.
Non calcium based binders
should be considered
in patients with complicated diabetes
mellitus, vascular calcifications and persistent inflammation. Iron based compounds
could be a good option in case of iron deficiency [5].
Take home message:
Preventing severe hyperphosphatemia remains an important aim in the management of patients
with kidney failure. However, the continuous monitoring of serum phosphate is sometimes difficult and lower levels of serum phosphate
are not significantly correlated with better
disease outcome. The choice of phosphorus binders should be studied carefully for each patients according
to his history
and personal factors. More randomized controlled trials are needed to confront different binders available.
References:
[1] Palmer SC, Hayen A, Macaskill P, Pellegrini F, Craig
JC, Elder GJ, et al. Serum levels of phosphorus, parathyroid hormone,
and calcium and risks of death and cardiovascular disease in individuals with chronic kidney disease: a systematic review and meta-analysis. JAMA. 2011 ;
305 :1119-27.
[2] Navaneethan SD, Palmer SC, Vecchio
M, Craig JC, Elder GJ, Strippoli
GF. Phosphate binders for preventing and treating
bone disease in chronic kidney disease patients. Cochrane
Database Syst Rev. 2011 ;6 :CD006023.
[3] Shantouf R, Ahmadi N, Flores F, Tiano J, Gopal A, Kalantar-Zadeh K, et al. Impact of phosphate
binder type on coronary
artery calcification in hemodialysis patients. Clin Nephrol. 2010; 74:12-8.
[4] Jamal SA, Vandermeer B, Raggi P, Mendelssohn DC, Chatterley T, Dorgan M, et al. Effect of calcium-based versus non-calcium-based phosphate binders
on mortality in patients
with chronic kidney
disease: an updated systematic review and meta-analysis. Lancet. 2013; 382:1268-77.
[5] Kidney Disease: Improving Global Outcomes (KDIGO)
CKDMBD Work Group. KDIGO clinical practice guideline for
the
diagnosis, evaluation, prevention, and treatment of chronic kidney disease-mineral and bone disorder
(CKD-MBD). Kidney
Int. 2009;76: S1-130.
Citation: Ait Faqih S. Phosphate binders in patients with chronic kidney disease: Between the new and the old. Junior Medical Research. 2019; 2(1):2-3. Ait Al Faqih © All rights are reserved. Submit your manuscript: www.jmedicalresearch.com
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Citation: Ait Al Fauih S. Phosphate binders in patients with chronic kidney disease: Between the new and the old. Junior Medical Research. 2019; 2(1):2-3. Ait Al Faqih © All rights are reserved. Submit your manuscript: www.jmedicalresearch.com