SEVELAMER HYDROCHLORIDE
Clinical safety rating: safe
Can decrease the absorption of many other drugs administer other drugs 1 hour before or 3 hours after Can cause GI side effects and hypocalcemia.
Sevelamer hydrochloride is a phosphate-binding polymer that binds dietary phosphate in the gastrointestinal tract, preventing its absorption and thereby reducing serum phosphate levels.
| Metabolism | Sevelamer hydrochloride is not absorbed systemically and is not metabolized. It is excreted unchanged in the feces. |
| Excretion | Sevelamer hydrochloride is not absorbed systemically; it is eliminated entirely in the feces as the unchanged polymer. No renal or biliary elimination occurs. |
| Half-life | Not applicable; sevelamer is not absorbed. The polymer acts locally in the gastrointestinal tract and does not have a measurable plasma half-life. |
| Protein binding | Not applicable; sevelamer is not absorbed and does not bind to plasma proteins. |
| Volume of Distribution | Not applicable; sevelamer is not absorbed and remains within the gastrointestinal lumen; thus, it does not have a volume of distribution. |
| Bioavailability | Sevelamer hydrochloride is not absorbed and has negligible systemic bioavailability (<0.001% absorbed). It acts locally in the GI tract. |
| Onset of Action | Sevelamer hydrochloride begins to bind dietary phosphate immediately upon ingestion; however, measurable reductions in serum phosphate may take up to 2 weeks of regular dosing to achieve clinical effect. |
| Duration of Action | The binding action lasts as long as the drug remains in the gastrointestinal tract, typically for the duration of the dosing interval (e.g., 8 hours with each meal). The effect on serum phosphate levels is sustained with continued administration. |
| Molecular Weight | Sevelamer hydrochloride is a cross-linked poly(allylamine hydrochloride) polymer; molecular weight is high (average > 1,000,000 Da) and not precisely defined as a single entity. |
Initial dose: 800-1600 mg orally three times daily with meals. Titrate by 800 mg per meal at 2-week intervals based on serum phosphorus levels. Maintenance: typically 2.4-4.8 g/day divided with meals.
| Dosage form | TABLET |
| Renal impairment | No dose adjustment required for renal impairment; drug is not systemically absorbed. Contraindicated in patients with hypophosphatemia or bowel obstruction. |
| Liver impairment | No dose adjustment needed; drug is not metabolized by the liver and is not absorbed systemically. |
| Pediatric use | Children ≥6 years: initial 800-1600 mg/day divided with meals, titrate based on serum phosphorus. Maximum 13 g/day. Safety and efficacy not established in children <6 years. |
| Geriatric use | No specific dose adjustment; use with caution due to increased risk of gastrointestinal adverse effects. Monitor serum phosphorus and calcium levels regularly. |
| 1st trimester | Limited human data; animal studies show no teratogenic effects. Use only if clearly needed. |
| 2nd trimester | May reduce absorption of fat-soluble vitamins and folic acid; monitor levels. Use only if clearly needed. |
| 3rd trimester | May cause hypophosphatemia in neonate if used near term; monitor maternal phosphate levels. |
Clinical note
Can decrease the absorption of many other drugs administer other drugs 1 hour before or 3 hours after Can cause GI side effects and hypocalcemia.
| FDA category | Animal |
| Placental transfer | Not expected to cross placenta due to high molecular weight and non-absorbed nature; no data available. |
| Breastfeeding |
■ FDA Black Box Warning
None.
| Common Effects | Nausea |
| Serious Effects |
Bowel obstructionHypophosphatemia
| Precautions | May cause bowel obstruction, perforation, or impaction, especially in patients with gastrointestinal disorders or prior surgery, Monitor for gastrointestinal bleeding and severe constipation, May cause decreased absorption of fat-soluble vitamins (A, D, E, K) and folic acid, May cause metabolic acidosis in susceptible patients, Use with caution in patients with dysphagia, swallowing disorders, or severe gastrointestinal motility disorders |
| Food/Dietary | Take sevelamer hydrochloride with meals to bind dietary phosphate. Avoid phosphate-rich foods (e.g., dairy, nuts, colas) per renal diet. No direct food-drug interactions but dosing aligns with meal timing. |
Loading safety data…
| Sevelamer is not absorbed systemically (oral administration, non-absorbed polymer), so exposure to nursing infant is negligible. Considered compatible with breastfeeding. |
| Lactation Rating | Safe |
| Teratogenic Risk | Sevelamer hydrochloride is not absorbed systemically; therefore, no direct fetal exposure is expected. No teratogenic effects have been observed in animal studies. Risk cannot be excluded, but based on mechanism, risk is low. |
| Fetal Monitoring | Monitor serum phosphate, calcium, and bicarbonate levels periodically. No specific fetal monitoring required. |
| Fertility Effects | No adverse effects on fertility observed in animal studies. No human data available. |
| Clinical Pearls | Sevelamer hydrochloride, a non-absorbed phosphate binder, is indicated for hyperphosphatemia in chronic kidney disease (CKD) patients on dialysis. Unlike calcium-based binders, it does not contribute to hypercalcemia and may reduce serum uric acid and cholesterol. Administer with meals for efficacy. Monitor serum phosphate, calcium, and bicarbonate due to potential acidosis. Avoid in bowel obstruction and hypophosphatemia. |
| Patient Advice | Take this medication exactly as prescribed, with meals and as directed by your healthcare provider. · Swallow tablets whole; do not crush, chew, or break them. · Adhere to your prescribed dietary phosphate restrictions while taking this medication. · Report any symptoms of bowel obstruction (severe constipation, stomach pain, bloating) or allergic reactions. · Keep all appointments for blood tests to monitor phosphate, calcium, and bicarbonate levels. |