Phosphate binders are

medication Medication (also called medicament, medicine, pharmaceutical drug, medicinal product, medicinal drug or simply drug) is a drug used to medical diagnosis, diagnose, cure, treat, or preventive medicine, prevent disease. Drug therapy (pharmaco ...

s used to reduce the absorption of dietary

phosphate Phosphates are the naturally occurring form of the element phosphorus. In chemistry, a phosphate is an anion, salt, functional group or ester derived from a phosphoric acid. It most commonly means orthophosphate, a derivative of orthop ...

; they are taken along with meals and snacks. They are frequently used in people with

chronic kidney failure Chronic kidney disease (CKD) is a type of long-term kidney disease, defined by the sustained presence of abnormal kidney function and/or abnormal kidney structure. To meet criteria for CKD, the abnormalities must be present for at least three mo ...

(CKF), who are less able to excrete phosphate, resulting in an elevated serum phosphate.

Mechanism of action

These agents work by binding to

in the

GI tract The gastrointestinal tract (GI tract, digestive tract, alimentary canal) is the tract or passageway of the digestive system that leads from the mouth to the anus. The tract is the largest of the body's systems, after the cardiovascular system. T ...

, 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 Magnesium is a chemical element; it has Symbol (chemistry), symbol Mg and atomic number 12. It is a shiny gray metal having a low density, low melting point and high chemical reactivity. Like the other alkaline earth metals (group 2 ...

aluminium Aluminium (or aluminum in North American English) is a chemical element; it has chemical symbol, symbol Al and atomic number 13. It has a density lower than that of other common metals, about one-third that of steel. Aluminium has ...

calcium Calcium is a chemical element; it has symbol Ca and atomic number 20. As an alkaline earth metal, calcium is a reactive metal that forms a dark oxide-nitride layer when exposed to air. Its physical and chemical properties are most similar to it ...

, or

lanthanum Lanthanum is a chemical element; it has symbol La and atomic number 57. It is a soft, ductile, silvery-white metal that tarnishes slowly when exposed to air. It is the eponym of the lanthanide series, a group of 15 similar elements bet ...

salts) that react with phosphate and form an

insoluble In chemistry, solubility is the ability of a substance, the solute, to form a solution with another substance, the solvent. Insolubility is the opposite property, the inability of the solute to form such a solution. The extent of the solub ...

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. 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. 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.

Medical use

For people with chronic kidney failure, controlling serum phosphate is important because it is associated with bone pathology and regulated together with serum

by the

parathyroid hormone Parathyroid hormone (PTH), also called parathormone or parathyrin, is a peptide hormone secreted by the parathyroid glands that regulates serum calcium and phosphate through its actions on the bone, kidneys, and small intestine. PTH incre ...

(PTH).

Adverse effects

Calcium carbonate * GI effects (nausea, vomiting, constipation) * Risk of cardiovascular calcification * Risk of hypercalcemia Lanthanum carbonate * GI obstruction * Bile duct obstruction * Hepatic impairment * No hypercalcemia risk Sevelamer carbonate * GI effects (nausea, vomiting, constipation, flatulence) * No hypercalcemia risk

Choice of agent

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.

Types

* Calcium acetate/magnesium carbonate

References

# Lederer E, Ouseph R, Erbeck K. Hyperphosphatemia, eMedicine.com, URL
Hyperphosphatemia: Practice Essentials, Background, Pathophysiology
Accessed on July 14, 2005. #

External links

High Phosphate Control - Official Fosrenol Homepage

Phosphate Binders: What Are They And How Do They Work?
- American Association of Kidney Patients*

- National Kidney Foundation

- Northwest Kidney Centers - a center that provides services for people with ESRD in the

Seattle Seattle ( ) is the most populous city in the U.S. state of Washington and in the Pacific Northwest region of North America. With a population of 780,995 in 2024, it is the 18th-most populous city in the United States. The city is the cou ...

area.
High Phosphate - Phosphorus Control
- Information for healthcare professionals on the treatment and management of hyperphosphatemia

Common Phosphate Binders

*

- medlineplus.org

- medlineplus.org
Sevelamer
- Renvela.com {{Drugs for treatment of hyperkalemia and hyperphosphatemia Nephrology procedures