sevelamer carbonate / sevelamer hydrochloride
Brand: Renvela (carbonate), Renagel (hydrochloride)
Prototype Drug
Drug Class: phosphate binder
Drug Family: electrolyte agent
Subclass: non-calcium, non-metal polymer phosphate binder
Organ Systems: renal
Mechanism of Action
Cross-linked polyallylamine polymer that binds dietary phosphate via ion exchange and hydrogen bonding in the GI tract; lacks calcium, magnesium, and aluminum, avoiding the mineral-loading complications associated with traditional phosphate binders; also modestly lowers LDL cholesterol by binding bile acids.
dietary phosphate (GI lumen)
Indications
- hyperphosphatemia in chronic kidney disease (both dialysis and non-dialysis patients)
Contraindications
- bowel obstruction
- hypophosphatemia
- hypersensitivity
Adverse Effects
Common
- nausea
- vomiting
- diarrhea
- constipation
- dyspepsia
- abdominal pain
Serious
- intestinal obstruction (rare)
- fecal impaction (rare with high doses)
Pharmacokinetics (ADME)
| Absorption | not systemically absorbed; acts exclusively in the GI lumen |
| Distribution | confined to GI tract |
| Metabolism | not metabolized |
| Excretion | fecal with bound phosphate |
| Half-life | N/A |
| Onset | phosphate lowering within 1-2 weeks of consistent dosing |
| Peak | N/A |
| Duration | requires administration with each meal for sustained effect |
| Protein Binding | N/A |
| Vd | N/A |
Drug Interactions
| Drug / Agent | Mechanism | Severity |
|---|---|---|
| ciprofloxacin | sevelamer reduces ciprofloxacin bioavailability by approximately 50%; avoid simultaneous administration | major |
| levothyroxine | sevelamer binds thyroid hormone in the GI tract; separate by several hours | moderate |
| cyclosporine, tacrolimus, mycophenolate | sevelamer may reduce absorption of immunosuppressants; monitor levels closely in transplant patients | moderate |
| fat-soluble vitamins (A, D, E, K) | may impair absorption by binding bile acids; supplement separately | moderate |
Nursing Considerations
- Administer sevelamer with meals — it must be taken with food to bind dietary phosphate in the GI lumen; tablets should be swallowed whole (not crushed or chewed) and powder packets mixed thoroughly with water before swallowing.
- Monitor serum phosphate, calcium, and bicarbonate levels regularly; sevelamer carbonate (Renvela) raises bicarbonate slightly and may benefit patients with CKD metabolic acidosis, while sevelamer HCl (Renagel) can worsen acidosis.
- Counsel patients on phosphate-restricted diet to reinforce dietary compliance alongside pharmacological therapy; sevelamer dose adjustments are typically guided by serum phosphate with a target of 3.5-5.5 mg/dL in dialysis patients.
- Separate sevelamer from fluoroquinolones and other interacting medications by at least 2 hours; inform transplant recipients that immunosuppressant levels must be monitored more carefully when sevelamer is initiated or doses are changed.
Clinical Pearls
- Sevelamer's non-calcium, non-aluminum composition makes it the preferred phosphate binder in patients with hypercalcemia, vascular calcification, or who are at risk for excess calcium loading — a key advantage over calcium-based binders.
- Sevelamer's modest LDL-lowering effect (approximately 20-30% reduction) occurs via bile acid binding in the GI tract, potentially providing additional cardiovascular benefit beyond phosphate control in CKD patients.
Safety Profile
Pregnancy use-with-caution
Lactation generally-safe
Renal Adjustment Not required
Hepatic Adjustment Not required
TDM Not required
Concordance Terms
Cross-referenced clinical concepts — click any term to see all content where it appears.