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Phosphate binder

From Wikipedia, the free encyclopedia

Phosphate binders are medications used to reduce the absorption of dietary phosphate; they are taken along with meals and snacks. They are frequently used in people with chronic kidney failure (CKF), who are less able to excrete phosphate, resulting in an elevated serum phosphate.

Mechanism of action

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These agents work by binding to phosphate in the GI tract, thereby making it unavailable to the body for absorption. Hence, these drugs are usually taken with meals to bind any phosphate that may be present in the ingested food. Phosphate binders may be simple molecular entities (such as magnesium, aluminium, calcium, or lanthanum salts) that react with phosphate and form an insoluble compound.

Calcium carbonate

Calcium-based phosphate binders, such as calcium carbonate, directly decrease phosphate levels by creating insoluble calcium–phosphate complexes which gets eliminated in the feces.[1]

Lanthanum carbonate

Non-calcium-based phosphate binders, including lanthanum carbonate, form insoluble complexes with phosphates in food, thereby reducing the amount of phosphate in the body.[1]

Sevelamer carbonate

Sevelamer is an insoluble polymeric amine, which is protonated once in the intestines and this allows it to bind dietary phosphate. Phosphates are eliminated along with sevelamer, leading to a decrease in the body's phosphate levels.[1]

Medical use

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For people with chronic kidney failure, controlling serum phosphate is important because it is associated with bone pathology and regulated together with serum calcium by the parathyroid hormone (PTH).[1]

Adverse effects

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Calcium carbonate

  • GI effects (nausea, vomiting, constipation)[2]
  • Risk of cardiovascular calcification[3]
  • Risk of hypercalcemia[3]

Lanthanum carbonate

  • GI obstruction[2]
  • Bile duct obstruction[2]
  • Hepatic impairment[2]
  • No hypercalcemia risk[3]

Sevelamer carbonate

  • GI effects (nausea, vomiting, constipation, flatulence)[2]
  • No hypercalcemia risk[3]

Choice of agent

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There have been limited trials comparing phosphate binders to placebo in the treatment of hyperphosphatemia in people with chronic kidney disease. When compared with people receiving calcium-based binders, people taking sevelamer have a reduced all-cause mortality.[4]

Types

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Summary of Common Oral Phosphate Binders[5]
Phosphate Binder Brands Advantages Disadvantages
Aluminum salts Alucaps Calcium free Risk of aluminum toxicity
Basaljel High binder efficiency regardless of pH Requires frequent monitoring-extra cost
Cheap
Moderate tablet burden
Calcium carbonate Calcichew Aluminum free Calcium containing-potential risk of hypercalcemia and ectopic calcification
Titralac Moderate binding efficacy Parathyroid hormone oversuppression
Relatively low cost Gastrointestinal side effects
Moderate tablet burden Efficacy pH dependent
Chewable
Calcium acetate Lenal Ace Aluminum free Calcium containing-potential risk of hypercalcemia and ectopic calcification
PhosLo Higher efficacy than calcichew/sevelamer Parathyroid hormone oversuppression
Moderately cheap Gastrointestinal side effects
Lower calcium load than calcium carbonate Large tablets & capsules, nonchewable formulation
Sevelamer hydrochloride/Sevelamer carbonate Renagel Aluminium and calcium free Relatively costly
Renvela No gastrointestinal absorption High pill burden
Moderate efficacy Large tablets, nonchewable formulation
Reduces total and low-density lipoprotein cholesterol Gastrointestinal side effects
Binds fat-soluble vitamins
Lanthanum carbonate Fosrenol Aluminum and calcium free Relatively costly
Minimal gastrointestinal absorption Gastrointestinal side effects
High efficacy across full pH range Larger tablet size may cause choking if not chewed well
Chewable formulation
Palatable
Low tablet burden
Ferric Citrate Auryxia Iron based Very costly
Tablets can be toxic to young children
Stool discoloration - may turn them black, obscuring intestinal bleeding

References

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  1. ^ a b c Daoud, Kirollos; Anwar, Nihad; Nguyen, Timothy (2023). "The Role of Iron-Based Phosphate Binder in the Treatment of Hyperphosphatemia". Nephrology Nursing Journal. 50 (2): 140. doi:10.37526/1526-744x.2023.50.2.140. ISSN 1526-744X.
  2. ^ a b c d e Daoud, Kirollos; Anwar, Nihad; Nguyen, Timothy (2023). "The Role of Iron-Based Phosphate Binder in the Treatment of Hyperphosphatemia". Nephrology Nursing Journal. 50 (2): 140. doi:10.37526/1526-744x.2023.50.2.140. ISSN 1526-744X.
  3. ^ a b c d Jadav, Paresh R.; Husain, S. Ali; Mohan, Sumit; Crew, Russell (May 2022). "Non calcium phosphate binders - Is there any evidence of benefit". Current Opinion in Nephrology & Hypertension. 31 (3): 288–296. doi:10.1097/MNH.0000000000000796. ISSN 1062-4821 – via Ovid.
  4. ^ Patel, L; Bernard, LM; Elder, GJ (14 December 2015). "Sevelamer versus calcium-based binders for treatment of hyperphosphatemia in CKD: a meta-analysis of randomized controlled trials". Clinical Journal of the American Society of Nephrology. 11 (2): 232–244. doi:10.2215/CJN.06800615. PMC 4741042. PMID 26668024.
  5. ^ Burtis, C.A.; Ashwood, E.R. and Bruns, D.E. Tietz Textbook of Clinical Chemistry and Molecular Diagnostics. 5th Edition. Elsevier. pp1552
  1. ^ Lederer E, Ouseph R, Erbeck K. Hyperphosphatemia, eMedicine.com, URL: Hyperphosphatemia: Practice Essentials, Background, Pathophysiology, Accessed on July 14, 2005.
  2. ^ Spiegel, David M.; Farmer, Beverly; Smits, Gerard; Chonchol, Michel (2007). "Magnesium Carbonate is an Effective Phosphate Binder for Chronic Hemodialysis Patients: A Pilot Study". Journal of Renal Nutrition. 17 (6): 416–22. doi:10.1053/j.jrn.2007.08.005. PMID 17971314.
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Common Phosphate Binders

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