How Do PO4 Scavengers Work?

PO4 (phosphate) scavengers are medications used to treat hyperphosphatemia (a condition where blood phosphorus levels are elevated than normal). Hyperphosphatemia is mainly seen in patients with chronic kidney disease, as the ability of the kidneys to remove phosphorus reduces, leading to an increase in blood phosphorus levels.

PO4 is a charged particle that contains mineral phosphorus that is essential for the repair and building of bones and teeth, nerve functions, and muscular contractions in the body. Excess phosphorus weakens bones, as it pulls out calcium from the bones increasing serum calcium levels. The free phosphorus and calcium deposit in the blood vessels, lungs, eyes, and heart and increases the risk for heart attack, stroke, or death.

PO4 scavengers are dietary phosphate binders; they promote the binding of phosphate in the gastrointestinal tract to reduce hyperphosphatemia. These drugs bind with the dietary phosphate to form a complex that decreases the absorption of phosphate in the gastrointestinal tract and lowers the phosphate concentration in the serum. The formed phosphate complex is eliminated through feces. 

Lanthanum decreases both serum phosphate and calcium levels, whereas sevelamer does not change calcium, aluminum, or bicarbonate concentrations while decreasing phosphate. Ferric citrate also increases iron levels and treats iron deficiency in anemia.

PO4 scavengers are given as oral tablets and oral suspension used to treat:

• Hyperphosphatemia
• Serum phosphorus regulation
• Reduction of serum phosphate in patients with end-stage renal disease
• Hyperphosphatemia in end-stage renal failure (on dialysis)
• Iron deficiency anemia

Side effects of PO4 scavengers may include:

• Nausea and vomiting 
• Diarrhea
• Constipation 
• Headache 
• Upper respiratory tract infection
• Arrhythmias (irregular heartbeats)
• Hypertension
• Tooth discoloration
• Hypophosphatemia 
• Hypercalcemia 
• Hyperkalemia 
• Dialysis graft complication/occlusion
• Dyspepsia
• Abdominal pain
• Peritonitis 
• Intestinal obstruction and perforation 
• Muscle and joint pains
• Confusion 
• Anaphylaxis (life-threatening allergic reactions) 

The information contained herein is not intended to cover all possible side effects, precautions, warnings, drug interactions, allergic reactions, or adverse effects. Check with your doctor or pharmacist to make sure these drugs do not cause any harm when you take them along with other medicines. Never stop taking your medication and never change your dose or frequency without consulting your doctor.

Generic and brand names of PO4 scavengers include:

• Auryxia
• Calcium acetate
• Calphron
• Eliphos
• Ferric citrate
• Fosrenol
• Lanthanum carbonate
• PhosLo
• Phoslyra
• Renagel
• Renvela
• Sevelamer
• Sucroferric oxyhydroxide
• Velphoro