Calcium Carbonate versus Calcium Acetate as Phosphate binder
Ph D: Neven Mohamed
For
many years, calcium-containing phosphate binders (calcium acetate and calcium
carbonate) were considered the best choice in the treatment of hyperphosphatemia,
due to they are effective, possessed only moderate side-effects
and suppressed parathormone levels with the intention of counteracting
progression of secondary hyperparathyroidism. In two head-to-head observational
studies (CARE, ARNOS), calcium-containing binders showed signals of clinical
superiority versus the comparator sevelamer-HCl.[1.2]
Nevertheless, calcium may be absorbed significantly, which may result in a
positive calcium balance and actively contribute progressive cardiovascular and
soft-tissue calcification in patients at risk.[3]
Calcium
acetate has similar effect on serum phosphate levels as compared to calcium
carbonate in patients on maintenance haemodialysis. However, calcium acetate
results in lesser frequency of hypercalcaemia as compared to calcium carbonate.
Tolerance to both drugs was similar, though patients complained of more muscle
cramps while taking calcium acetate.
Calcium Salt
|
Calcium Content
|
calcium acetate
|
253 mg (12.7 mEq) per
g (20% elemental calcium)
|
calcium carbonate
|
400 mg (20 mEq) per g
(40% elemental calcium)
|
Hyperphosphatemia
in Chronic Renal Failure
Oral
Recommended initial dose of calcium acetate is 1.334 g (338 mg of calcium) three times daily with meal; gradual increase in dose according to serum phosphate concentrations, prevents occurring of hypercalcemia.
Manufacturer states that
most patients require about 2–2.67 g (about 500–680 mg of calcium) with each
meal4. However, some experts recommend limiting dosage of calcium
provided by phosphate binders to ≤1.5 g daily and limiting total calcium intake
(including dietary calcium) to ≤2 g daily; dialysis patients who remain
hyperphosphatemic despite such therapy should receive a calcium-containing
phosphate binder in combination with a non-calcium-, non-aluminum-,
non-magnesium-containing phosphate binder.5
References:
1.
Qunibi WY, Hootkins RE, McDowell LL, et al. Treatment of
hyperphosphatemia in hemodialysis patients: the Calcium Acetate Renagel
Evaluation (CARE Study). Kidney Int 2004; 65:1914–1926.
2.
Jean G, Lataillade D, Genet L, et al. Calcium carbonate, but
not sevelamer, is associated with better outcomes in hemodialysis patients:
results from the French ARNOS study. Hemodial Int 2011; 15:485–492.
3.
Goodman WG, Goldin J, Kuizon BD, et al. Coronary-artery
calcification in young adults with end-stage renal disease who are undergoing
dialysis. N Engl J Med 2000; 342:1478–1483.
4.
Braintree Laboratories. PhosLo (calcium
acetate) tablets prescribing information (dated May 1992). In: Physicians’ desk
reference. 52nd ed. Montvale, NJ; 1998:733-4.
5-National Kidney Foundation.
Kidney Disease Outcomes Quality Initiative (K/DOQI) clinical practice
guidelines for bone metabolism and disease in chronic kidney disease. Guideline
5. Use of phosphate binders in CKD. 2003. Available at . Accessed 2005 Mar 22
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