Sevelamer HCL (RENAVEL®) v/s Sevelamer Carbonate (NEOVEL®)
Table of Content:
What is Sevelamer?
Sevelamer is a phosphate chelator or phosphate binder that binds with phosphate ion in the gut (dietary phosphate) preventing the absorption of the phosphate in the blood stream consequently decreasing the serum phosphate level without causing hypercalcemia (increase in calcium level).
The principal mechanism behind this binding action is the structure of the sevelamer. Sevelamer is an ion-exchange resin-meaning a polymer that exchanges its ions (H⁺, Cl⁻, etc.) with ions in the gut. Sevelamer existed in two forms:
- Sevelamer HCL
- Sevelamer Carbonate
So, as per these forms, sevelamer either exchange HCL or carbonate with the phosphate ion in the gut to reduce the absorption of phosphate.
Why there is a need for phosphate binding?
Patients suffering from the chronic kidney disease (CKD), especially the end stage renal disease have reduced glomerular filtration rate due to which the elimination of phosphate gets reduced causing hyperphosphatemia in such patients. High level of phosphate poses a number of health problems including the bone resorption due to secondary hyperparathyroidism, arteriosclerosis, ischemia, and nephron injury etc.
Thus, there is a need to combat this high level of phosphate in the body in order to prevent further damage to the body. For phosphate binding various medication are available in the market.
Available Phosphate binders:
Various phosphate binder that are often use in the patient of CKD are as follow:
- Calcium Acetate (PHOSLO® or LOPHOS®)
- Calcium carbonate
- Ferric Citrate
- Aluminium and magnesium-based binders are also available but rarely used due to the risk of associated toxicity.
- Sevelamer
Calcium base binders though inexpensive and easily available, are associated with the risk of hypercalcemia especially in the patient who already have high calcium level in the body. So, its usage depends upon the calcium level in the body. While sevelamer though expensive, have no associated risk of hypercalcemia or other toxicity, as it doesn’t get absorbs in the body. However, which salt form of sevelamer (i.e. Sevelamer HCL and Sevelamer Carbonate) is being used does matters!
Difference between Sevelamer HCL and Sevelamer Carbonate:
Sevelamer HCL and Sevelamer Carbonate shares many common aspects, though there exist some differences as well. Which are given below:
Characteristic feature | Sevelamer HCL | Sevelamer Carbonate |
“Similarities” | ||
Indication | Hyperphosphatemia in CKD | Hyperphosphatemia in CKD |
Efficacy | Highly efficacious in decreasing serum phosphate level | Same effect as that of sevelamer HCL |
Administration | Orally administered concomitantly with meals | orally administered concomitantly with meals |
Absorption | Non-absorbable | Non-absorbable |
Elimination | Eliminated via feces | Eliminated via feces |
“Differences” | ||
Metabolic acidosis | Does causes Metabolic acidosis | Doesn’t cause metabolic acidosis |
Effect on serum bicarbonate and Blood pH | It decreases serum bicarbonate level and blood pH | It doesn’t decrease serum bicarbonate level and Blood pH |
Usage limitation | It is only used in patients who are on dialysis | It can be used in both dialysis and non-dialysis patients. |
Brand Available | RENAVEL® RENVELA® SALVER® PHOSPHAMER® RENAGEL® | NEOVEL® SELCARB®
|
Therefore, in patients who are suffering from or at risk of developing metabolic acidosis, or in haemodialysis patients where an increase in bicarbonate levels and blood pH is desired, sevelamer carbonate is the preferred choice. Otherwise the efficacy of both of the salts are same. Where a patient is not at a risk of metabolic acidosis, sevelamer HCL can be used. Secondly, Sevelamer HCL can only be given to the patients who are on dialysis.
Despite any of the above-mentioned difference, there is no need for the dose adjustment in case of switching from one salt form to the other salt form, keeping the potency same.
Adult Dosage plan of Sevelamer:
Now let’s take a look at general adult dosage plan of SEVELAMER:
|
Clinical Situation |
Recommended Dosage |
|
Initial Dose (Phosphate Binder–Naive Patients) |
|
|
Serum phosphate > 9 mg/dL |
1600 mg orally, three times daily with meals |
|
Serum phosphate 7.5–9 mg/dL |
1200–1600 mg orally, three times daily with meals |
|
Serum phosphate 5.5–7.5 mg/dL |
800 mg orally, three times daily with meals |
|
Titration |
Adjust dose by 400–800 mg per meal every 2 weeks until target phosphate level is reached. Average daily dose: ~7.2 g. Maximum studied daily dose: 14 g in dialysis patients. |
|
Maintenance Dose (Target: ≤ 5.5 mg/dL) |
|
|
Serum phosphate > 5.5 mg/dL |
Increase dose by 400–800 mg per meal |
|
Serum phosphate 3.5–5.5 mg/dL |
Continue current dose |
|
Serum phosphate < 3.5 mg/dL |
Decrease dose by 400–800 mg per meal |
|
Switching from Calcium Acetate |
|
|
667 mg calcium acetate |
Substitute with 800 mg sevelamer (hydrochloride or carbonate) |
|
1334 mg calcium acetate |
Substitute with 1600 mg sevelamer |
|
2001 mg calcium acetate |
Substitute with 2400 mg sevelamer |
Drug interactions of Sevelamer:
Sevelamer can interact with certain medications and reduce their bioavailability, potentially diminishing their therapeutic effect. To minimize this risk, it is recommended to maintain an administration gap between sevelamer and interacting drugs. Some of the most common drug interactions with sevelamer are mentioned below:
Adverse Effects of Sevelamer:
Common adverse effects of sevelamer includes:
- Dyspepsia
- Nausea
- Vomiting
- Diarrhea
- Abdominal pain
- Nasopharyngitis
- Pruritic
- Arthralgia
- Bronchitis
- Limbs pain
Notes: limbs pain, arthralgia, bone pain or cramps are usually associated with extreme reduction in the phosphate level. Also, vitamin deficiency especially low vitamin D levels decrease calcium absorption which can also cause bone pain, osteomalacia, muscle weakness. It is also noteworthy that changes in vitamin level due to sevelamer can impact patient’s immune system and increases the chances of infections.
References:
Kharsa, A., & Rout, P. (2024, September 14). Sevelamer. In StatPearls [Internet]. StatPearls Publishing. https://www.ncbi.nlm.nih.gov/books/NBK607999/ NCBI+1
Pai, A. B., & Shepler, B. M. (2009). Comparison of sevelamer hydrochloride and sevelamer carbonate: Risk of metabolic acidosis and clinical implications. Pharmacotherapy, 29(5), 554-561. https://doi.org/10.1592/phco.29.5.554
Lancashire & South Cumbria Formulary – Medicines Matter: Sevelamer switch. (2022, June 22). Lead Pharmacist, Renal Medicine; Reviewed by Ajay Dhaygude, Renal Consultant. https://www.lancashireandsouthcumbriaformulary.nhs.uk/docs/files/medications-matter-sevelamer-switch-lscmmg.pdf lancashireandsouthcumbriaformulary.nhs.uk+1
Fazeli, B., & Hajisalimi, B. (2022). Comparing the effect of sevelamer carbonate and sevelamer hydrochloride on plasma pH, bicarbonate and gastrointestinal complications in patients undergoing maintenance hemodialysis. Journal of Renal Endocrinology, 8, e25068. https://doi.org/10.34172/jre.2022.25068
Disclaimer:
This comparison is for informational and educational purposes only. It does not substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider before starting any medication.
