Renagel

Renagel (sevelamer hydrochloride) is a non-calcium, non-metal phosphate binder specifically formulated for the management of hyperphosphatemia in patients undergoing dialysis. It represents a critical therapeutic advancement by effectively reducing serum phosphate levels without contributing to calcium accumulation or systemic metal exposure, which are common limitations of traditional binders. By selectively binding dietary phosphate in the gastrointestinal tract, Renagel helps restore mineral balance, supporting long-term renal bone disease management and reducing the risk of cardiovascular calcification, a leading cause of mortality in end-stage renal disease. Its unique polymer-based mechanism offers a targeted approach to phosphate control, making it a cornerstone therapy in nephrology care.

Features

• Active ingredient: Sevelamer hydrochloride
• Formulation: Film-coated tablets (400 mg and 800 mg strengths)
• Mechanism: Non-absorbed polymeric phosphate binder
• Excipients: Colloidal silicon dioxide, stearic acid; tablet coating contains hypromellose and diacetylated monoglycerides
• Preservative-free, sugar-free composition
• No systemic absorption; acts locally within the gastrointestinal tract

Benefits

• Effectively lowers and maintains serum phosphate levels within target range (3.5–5.5 mg/dL)
• Reduces risk of vascular and soft tissue calcification by avoiding calcium loading
• Eliminates concerns about aluminum or metal accumulation associated with other binders
• May improve bone metabolism parameters in chronic kidney disease-mineral and bone disorder (CKD-MBD)
• Does not contribute to metabolic alkalosis
• May positively impact lipid profiles through modest LDL cholesterol reduction

Common use

Renagel is indicated for the control of serum phosphorus in patients with chronic kidney disease on hemodialysis. It is typically prescribed as part of a comprehensive management strategy that includes dietary phosphate restriction and adequate dialysis. The medication is used long-term to maintain phosphate balance and prevent the complications of hyperphosphatemia, including secondary hyperparathyroidism, renal osteodystrophy, and cardiovascular calcification. Treatment is usually initiated when serum phosphorus levels exceed 5.5 mg/dL despite dietary management.

Dosage and direction

The recommended starting dose for Renagel is 800–1600 mg taken orally with meals three times daily. The exact dosage should be individualized based on serum phosphate levels and tailored to each meal’s phosphate content. Tablets should be swallowed whole with water and should not be crushed, chewed, or broken. Dosage titration should occur in increments of 800 mg per meal at 2-week intervals based on serial serum phosphorus measurements. Most patients require 2400–4800 mg daily divided into three doses with meals. The maximum studied dose is 13 grams daily, though most patients achieve control at lower doses.

Precautions

• Renal function monitoring: While Renagel is not systemically absorbed, renal function should be regularly assessed as part of comprehensive CKD management
• Gastrointestinal effects: Patients may experience constipation, which can be managed with appropriate dietary fiber and fluid intake; severe cases may require dosage adjustment
• Vitamin levels: Long-term use may affect fat-soluble vitamin absorption; consider monitoring vitamins A, D, E, and K and folic acid levels annually
• Swallowing difficulty: Caution advised in patients with swallowing disorders or severe gastrointestinal motility issues
• Drug interactions: Separate administration of other medications by at least 1 hour before or 3 hours after Renagel dose
• Pregnancy and lactation: Use only if clearly needed; no adequate human studies exist

Contraindications

• Hypersensitivity to sevelamer hydrochloride or any component of the formulation
• Bowel obstruction of any type
• Hypophosphatemia
• Fecal impaction
• Patients with dysphagia or swallowing disorders who cannot swallow tablets whole
• Acute gastrointestinal paralysis or ileus

Possible side effect

Common (≥5%):

• Constipation (20%)
• Diarrhea (16%)
• Dyspepsia (15%)
• Nausea (9%)
• Abdominal pain (8%)
• Flatulence (7%)

Less common (1–5%):

• Vomiting
• Headache
• Pruritus
• Rash
• Infection

Rare (<1%):

• Intestinal obstruction
• Fecal impaction
• Bowel perforation (in patients with underlying GI disease)
• Esophageal tablet retention
• Allergic reactions

Drug interaction

• Ciprofloxacin: Renagel reduces bioavailability by approximately 50%; administer at least 2 hours before or 6 hours after Renagel
• Thyroid hormones: Reduced absorption; monitor thyroid function and separate administration by at least 4 hours
• Mycophenolate mofetil: Reduced MPA exposure; administer at least 2 hours before Renagel
• Fat-soluble vitamins: May decrease absorption of vitamins A, D, E, and K; monitor levels and supplement as needed
• Antiepileptic drugs: Potential reduced absorption of phenytoin, valproic acid; monitor levels and adjust dosage
• Oral contraceptives: Theoretical risk of reduced efficacy; consider alternative contraception methods

Missed dose

If a dose is missed, it should be taken as soon as remembered with food. However, if it is almost time for the next scheduled dose, the missed dose should be skipped and the regular dosing schedule resumed. Patients should not double the dose to make up for a missed dose. Consistency with meal-time dosing is crucial for optimal phosphate binding efficacy. If multiple doses are missed, serum phosphate levels should be monitored and dietary phosphate restriction reinforced until regular dosing resumes.

Overdose

Renagel overdose is unlikely to cause systemic toxicity due to lack of absorption. The most likely manifestations would be gastrointestinal effects such as severe constipation, abdominal discomfort, or potential bowel obstruction in susceptible individuals. Management is symptomatic and supportive. Severe constipation may require laxatives or enemas under medical supervision. There is no specific antidote. Hemodialysis is not effective for removal as the drug is not systemically absorbed. Patients should be monitored for electrolyte abnormalities, particularly hypophosphatemia if massive overdose occurs.

Storage

Store at controlled room temperature 20–25°C (68–77°F); excursions permitted to 15–30°C (59–86°F). Keep container tightly closed to protect from moisture. Keep out of reach of children and pets. Do not use if the blister pack or bottle seal is broken or missing. Do not transfer tablets to other containers unless specifically designed for medication storage. Discard any medication that is expired or no longer needed through proper medication take-back programs.

Disclaimer

This information is for educational purposes only and does not constitute medical advice. Treatment decisions should be made by qualified healthcare professionals based on individual patient characteristics. Always follow the prescribing information provided with the medication and consult with a nephrologist or pharmacist for specific guidance. Dosage adjustments should only be made under medical supervision. The full prescribing information contains complete details regarding warnings, precautions, and adverse reactions.

Reviews

Clinical studies demonstrate Renagel’s efficacy in maintaining serum phosphate levels below 5.5 mg/dL in approximately 60-70% of dialysis patients. Long-term extension studies show sustained phosphate control for up to 3 years of treatment. Nephrologists report particular value in patients with vascular calcification concerns or those intolerant to calcium-based binders. Patient satisfaction surveys indicate good tolerability despite gastrointestinal side effects, with most patients preferring Renagel over older phosphate binders due to fewer metal-related concerns and flexible dosing. Real-world evidence supports its role in reducing cardiovascular calcification progression when used as part of comprehensive CKD-MBD management.