Company:
Genzyme
Pharmacologic class:
Phosphate binder
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Active ingredient:
Sevelamer carbonate 800 mg; tabs.
Indication:
Control of serum phosphorus in patients with chronic kidney disease (CKD) on dialysis.
Pharmacology:
Patients with CKD can develop hyperphosphatemia as a result of retained phosphorus, which may lead to ectopic calcification. Hyperphosphatemia plays a role in the development of secondary hyperparathyroidism in CKD. In order to control patients’ serum phosphorus levels, phosphate binders are utilized in addition to dietary phosphorus and dialysis.
Sevelamer carbonate is a polymer that binds phosphorus in the dietary tract thereby decreasing the absorption of phosphorus. It also binds bile acids, which may interfere with normal fat absorption, including fat-soluble vitamins. Additionally it has been shown to reduce the mean total and LDL by 15%-31%.
Renvela is a calcium-free, metal-free, nonabsorbed phosphate binder. It works similarly to Renagel (sevelamer HCl, also from Genzyme) with the benefit of a carbonate buffer.
Clinical trials:
The efficacy of sevelamer to control serum phosphorus in CKD patients on dialysis was determined from the effects of the hydrochloride salt to bind phosphate. Six clinical trials were conducted; one of the six used sevelamer carbonate. In this trial,stage 5 CKD patients on hemodialysis were entered into a five-week sevelamer HCl run-in period and 79 patients were randomized to receive either sevelamer carbonate 800-mg tablets or sevelamer HCl 800-mg tablets for eight weeks each, with no intervening washout. Study dose during the crossover period was determined based on the sevelamer HCl dose during the run-in period on a gram-per-gram basis. The phosphate levels at the end of each of the two crossover periods were similar. Average actual daily dose was 6 g/day for both treatment groups. Thirty-nine of those completing the crossover portion of the study were entered into a two-week washout period during which patients were instructed not to take any phosphate binders; this confirmed the activity of sevelamer in this study.
Adults:
Take with meals. Patients not taking a phosphate binder: serum phosphorus >5.5 and <7.5 mg/dL: one tablet three times daily; ≥7.5 mg/dL: two tablets three times daily. May switch from sevelamer HCl on a gram-per-gram basis. Switching from calcium acetate: sevelamer carbonate 800 mg approximates calcium acetate 667 mg (see literature). Titrate by one tablet/meal at two-week intervals to keep serum phosphorus between 3.5 and 5.5 mg/dL; usual max 14 g/day.
Children:
Not recommended.
Contraindications:
Hypophosphatemia. Bowel obstruction.
Precautions:
Dysphagia. Swallowing disorders. Severe GI motility disorders. Major GI tract surgery. Monitor serum bicarbonate, chloride levels. Pregnancy (Cat. C). Labor and delivery.
Interactions:
May antagonize ciprofloxacin. Separate narrow therapeutic index drugs by one hour before or three hours after sevelamer, or consider monitoring (esp. with antiarrhythmics, antiepileptics).
Adverse reactions:
GI upset, constipation. How supplied: Tabs—30, 270
For more information, call 800.847.0069 or visit www.Renvela.com.
