Sevelamer – a phosphate binder for kidney bone disease

Sevelamer – a phosphate binder for kidney bone disease

Sevelamer is a medication used to control phosphate levels, primarily in patients with chronic kidney disease (CKD).

What is sevelamer?

• Sevelamer is a phosphate binder used to reduce high blood phosphate levels (hyperphosphataemia).

• It is most primarily used for patients with chronic kidney disease (CKD) who are on dialysis.

• Unlike some other binders, sevelamer is calcium-free and metal-free, meaning it lowers phosphate without raising calcium or aluminum levels in the body.

• By keeping phosphate levels in check, it helps protect your bones and reduces the risk of dangerous mineral deposits in your heart and blood vessels.

Note. Advantages: It is often chosen because it does not increase calcium levels (avoiding hypercalcaemia), making it safer for patients who cannot tolerate calcium-based binders – especially if they have had hypercalcaemia.

How it works

The mechanism of action of sevelamer involves ‘binding’ to phosphate in the digestive tract:

• When taken with meals, sevelamer attaches to the phosphate found in your food.

• This prevents the phosphate from being absorbed into your bloodstream.

• Instead, the bound phosphate passes safely through your system and is eliminated in your stool.

Who is sevelamer used for?

The main uses of sevelamer include the treatment of:

• Hyperphosphataemia (high blood phosphate) in adults with CKD, who are not on dialysis

• Patients on dialysis (both haemodialysis and peritoneal dialysis).

By controlling phosphate, sevelamer helps prevent secondary hyperparathyroidism and metabolic bone disease.

Dose

• Adults: The starting dose is usually 800 mg to 1600 mg taken three times a day with meals.

• Titration: Your doctor will adjust the dose based on your blood phosphate levels.

• Available as sevelamer carbonate (Renvela) or sevelamer hydrochloride (Renagel).

Note: Sevelamer must be taken with food to be effective. Tablets should be swallowed whole; do not crush, chew, or break them.

Side-effects

Most sevelamer side-effects are gastrointestinal, as the medicine stays within the digestive tract.

• Nausea and vomiting

• Diarrhea or constipation

• Indigestion or stomach pain

• Bloating and gas

Serious symptoms to report:

• Severe constipation or worsening ‘blockage’ feelings.

• Difficulty swallowing.

• Severe abdominal pain.

Monitoring

Your doctor should monitor:

• Blood Phosphate: To ensure the dose is effectively binding the phosphate from your diet.

• Blood Calcium and Bicarbonate: To maintain a healthy mineral balance.

• Vitamins: Because it binds substances in the gut, sevelamer can sometimes lower the absorption of vitamins D, E, K, and folic acid.