Phosphate binder

Medication used to reduce the absorption of phosphate 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

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

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).

Adverse effects

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

Summarize
Perspective

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

More information Brands, Advantages ...
Summary of Common Oral Phosphate Binders[5]
Phosphate BinderBrandsAdvantagesDisadvantages
Aluminum saltsAlucapsCalcium freeRisk of aluminum toxicity
BasaljelHigh binder efficiency regardless of pHRequires frequent monitoring-extra cost
Cheap
Moderate tablet burden
Calcium carbonateCalcichewAluminum freeCalcium containing-potential risk of hypercalcemia and ectopic calcification
TitralacModerate binding efficacyParathyroid hormone oversuppression
Relatively low costGastrointestinal side effects
Moderate tablet burdenEfficacy pH dependent
Chewable
Calcium acetateLenal AceAluminum freeCalcium containing-potential risk of hypercalcemia and ectopic calcification
PhosLoHigher efficacy than calcichew/sevelamerParathyroid hormone oversuppression
Moderately cheapGastrointestinal side effects
Lower calcium load than calcium carbonateLarge tablets & capsules, nonchewable formulation
Sevelamer hydrochloride/Sevelamer carbonateRenagelAluminium and calcium freeRelatively costly
RenvelaNo gastrointestinal absorptionHigh pill burden
Moderate efficacyLarge tablets, nonchewable formulation
Reduces total and low-density lipoprotein cholesterolGastrointestinal side effects
Binds fat-soluble vitamins
Lanthanum carbonateFosrenolAluminum and calcium freeRelatively costly
Minimal gastrointestinal absorptionGastrointestinal side effects
High efficacy across full pH rangeLarger 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
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References

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