SEVELAMER CARBONATE
Clinical safety rating: safe
Animal studies have demonstrated safety
Sevelamer carbonate is a phosphate-binding polymer that binds dietary phosphate in the gastrointestinal tract, thereby reducing phosphate absorption and serum phosphate levels. It also binds bile acids and may reduce LDL cholesterol.
| Metabolism | Sevelamer carbonate is not absorbed systemically; thus, it is not metabolized and is excreted unchanged in the feces. |
| Excretion | Sevelamer carbonate is not absorbed systemically; it acts locally in the gastrointestinal tract. Excretion is entirely fecal, with no renal or biliary elimination. The polymer is excreted unchanged in the feces. |
| Half-life | Not applicable. Sevelamer carbonate is not systemically absorbed and thus has no measurable plasma half-life. Its pharmacological effect correlates with gastrointestinal transit time, which is typically 24-48 hours. |
| Protein binding | 0%. Sevelamer carbonate is a non-absorbed polymer and does not bind to plasma proteins. |
| Volume of Distribution | Not applicable. As a non-absorbed drug, volume of distribution is effectively 0 L/kg. It remains within the gastrointestinal lumen. |
| Bioavailability | Oral: 0% systemically. Sevelamer carbonate is not absorbed; bioavailability refers to local (non-systemic) action only. |
| Onset of Action | Oral: Onset of serum phosphorus reduction occurs within 1-2 weeks of initiating therapy. Maximal effect is typically seen after 4-8 weeks of consistent dosing. |
| Duration of Action | Oral: Duration of action is dependent on dosing schedule; due to lack of systemic absorption, the effect is confined to the gastrointestinal tract. The phosphate-binding effect persists for 4-6 hours after a single dose, necessitating administration with meals three times daily. |
| Molecular Weight | Varies (polymer, average molecular weight ~ 100,000 Da) |
Adults: 800 to 1600 mg orally three times daily with meals, titrated according to serum phosphorus targets.
| Dosage form | FOR SUSPENSION |
| Renal impairment | No adjustment required for chronic kidney disease (CKD) or end-stage renal disease (ESRD) as drug is minimally absorbed and excreted renally. |
| Liver impairment | No dose adjustment necessary in hepatic impairment; drug is not hepatically metabolized. |
| Pediatric use | Children ≥6 years: Starting dose 800 to 1600 mg/day in divided doses with meals, based on body weight and serum phosphorus level; adjust by 400-800 mg increments every 2-4 weeks to target phosphorus within normal range. |
| Geriatric use | No specific dose adjustment; initiate at lower end of dosing range and monitor serum phosphorus and electrolytes due to potential for GI side effects and electrolyte disturbances. |
| 1st trimester | Sevelamer carbonate is not absorbed systemically; thus, maternal use is not expected to result in fetal exposure. However, data in pregnant women are limited. Use only if clearly needed. |
| 2nd trimester | Same as T1. No known fetal risk due to lack of systemic absorption. |
| 3rd trimester | Same as T1 and T2. No known fetal risk. |
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.
| Placental transfer | Not expected to cross the placenta due to lack of systemic absorption after oral administration. |
| Breastfeeding | Sevelamer carbonate is not absorbed systemically; therefore, it is unlikely to enter breast milk. However, due to lack of data in lactating women, caution is advised. Consider benefits and risks. |
■ FDA Black Box Warning
No FDA boxed warning.
| Common Effects | Nausea |
| Serious Effects |
Hypersensitivity to sevelamer or any component of the formulationBowel obstruction
| Precautions | Bowel obstruction, bleeding, perforation: Cases reported; monitor for constipation and gastrointestinal symptoms., Dysphagia and esophageal disorders: Use with caution in patients with swallowing disorders or severe gastrointestinal motility disorders., Reduced absorption of fat-soluble vitamins and folic acid: Monitor levels and supplement if needed., Hyperchloremic metabolic acidosis: May occur due to chloride-containing formulation (sevelamer hydrochloride), but sevelamer carbonate may reduce risk. |
| Food/Dietary | Take with meals to bind dietary phosphate; avoid high-phosphate foods (e.g., dairy, nuts, beans, colas). Sevelamer may reduce absorption of fat-soluble vitamins (A, D, E, K) and folic acid; consider supplementation. |
Loading safety data…
| Lactation Rating | L3 (Moderately Safe) - No systemic absorption expected, but limited data. |
| Teratogenic Risk | Sevelamer carbonate is not absorbed systemically, thus unlikely to pose direct teratogenic risk. No human or animal studies have demonstrated fetal harm. However, potential for maternal vitamin deficiency (e.g., vitamin D, folic acid) due to binding may indirectly affect fetal development. Use in pregnancy only if clearly needed. |
| Fetal Monitoring | Monitor serum phosphate, calcium, bicarbonate, vitamin D, and folate levels periodically due to potential binding. Assess maternal nutritional status. |
| Fertility Effects | No known direct effect on fertility. Potential for reduced absorption of nutrients (e.g., folic acid) could theoretically impact fertility, but no human data. |
| Clinical Pearls | Sevelamer carbonate is a non-absorbed phosphate binder used in chronic kidney disease (CKD) on dialysis. Unlike calcium-based binders, it does not contribute to hypercalcemia or adynamic bone disease. It may also lower LDL cholesterol. Administer with meals to bind dietary phosphate. Monitor serum phosphate and bicarbonate; can cause metabolic acidosis (chloride form) but carbonate form is less likely. Avoid in hypophosphatemia or bowel obstruction. |
| Patient Advice | Take with meals to control phosphate levels. · Swallow tablets whole; do not crush or chew. · Maintain a low-phosphate diet for best results. · Space other medications at least 1 hour before or 3 hours after sevelamer. · Report severe constipation, black tarry stools, or difficulty swallowing. |