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 edit
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 the food we eat; 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 & 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 edit
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 edit
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 edit
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 edit
| 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 edit
- ^ 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.
- ^ 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.
- ^ 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.
- ^ 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.
- ^ Burtis, C.A.; Ashwood, E.R. and Bruns, D.E. Tietz Textbook of Clinical Chemistry and Molecular Diagnostics. 5th Edition. Elsevier. pp1552
- ^ Lederer E, Ouseph R, Erbeck K. Hyperphosphatemia, eMedicine.com, URL: Hyperphosphatemia: Practice Essentials, Background, Pathophysiology, Accessed on July 14, 2005.
- ^ 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.
External links edit
- High Phosphate Control - Official Fosrenol Homepage*
- Phosphate Binders: What Are They And How Do They Work? - American Association of Kidney Patients*
- Phosphate Binders - National Kidney Foundation
- Phosphate Binders - Northwest Kidney Centers - a center that provides services for people with ESRD in the Seattle area.
- High Phosphate - Phosphorus Control - Information for healthcare professionals on the treatment and management of hyperphosphatemia
Common Phosphate Binders edit
- Hutchison, A. J.; Wilkie, M. (2012). "Use of magnesium as a drug in chronic kidney disease". Clinical Kidney Journal. 5 (Suppl 1): i62–i70. doi:10.1093/ndtplus/sfr168. PMC 4455824. PMID 26069822.
- Lanthanum - medlineplus.org
- Sevelamer - medlineplus.org
- Sevelamer - Renvela.com