Sevelamer

A phosphate binder used in the management of hyperphosphatemia

Chemical structure of Sevelamer

Sevelamer is a medication used to treat hyperphosphatemia (high blood phosphate levels) in patients with chronic kidney disease (CKD) who are on dialysis. It is a non-absorbed phosphate binder that works by binding phosphate in the gastrointestinal tract, thereby preventing its absorption into the bloodstream.

Medical uses

Sevelamer is primarily used to manage hyperphosphatemia in patients with CKD on dialysis. By controlling phosphate levels, it helps prevent complications such as bone disease and cardiovascular disease that are associated with high phosphate levels. Sevelamer is available in two forms: sevelamer hydrochloride and sevelamer carbonate. Both forms are effective in reducing serum phosphate levels.

Mechanism of action

Sevelamer acts by binding phosphate ions in the digestive tract. It is a polymeric compound that contains multiple amine groups, which become protonated in the acidic environment of the stomach. These protonated amine groups bind to negatively charged phosphate ions, forming an insoluble complex that is excreted in the feces. This reduces the absorption of phosphate from the diet, thereby lowering serum phosphate levels.

Side effects

Common side effects of sevelamer include gastrointestinal symptoms such as nausea, vomiting, diarrhea, and constipation. Some patients may experience abdominal pain or indigestion. Rarely, sevelamer can cause intestinal obstruction or perforation. Patients are advised to take sevelamer with meals to enhance its phosphate-binding effect.

Contraindications

Sevelamer is contraindicated in patients with bowel obstruction or known hypersensitivity to the drug. Caution is advised in patients with swallowing disorders or severe gastrointestinal motility disorders.

Pharmacokinetics

Sevelamer is not absorbed into the bloodstream and exerts its effects locally in the gastrointestinal tract. It is excreted unchanged in the feces. Because it is not systemically absorbed, it does not require dose adjustments based on renal or hepatic function.

Formulations

Sevelamer is available in tablet and powder form. The powder form can be mixed with water and taken orally. The choice of formulation may depend on patient preference and the ability to swallow tablets.

Related pages

• Chronic kidney disease
• Dialysis
• Hyperphosphatemia
• Phosphate binder