Sevelamer Carbonate

Sevelamer carbonate, a non-absorbed phosphate binding crosslinked polymer, free of metal and calcium. It contains multiple amines separated by one carbon from the polymer backbone. These amines exist in a protonated form in the intestine and interact with phosphate molecules through ionic and hydrogen bonding. By binding phosphate in the gastrointestinal tract and decreasing absorption, sevelamer carbonate lowers the phosphate concentration in the serum (serum phosphorus).

Starting dose: The recommended starting dose of Sevelamer Carbonate is 2.4 g (Three Sevelamer 800 mg tablets or Three Sevelamer 800 mg sachets of powder for oral suspension) or 4.8 g (Six Sevelamer 800 mg tablets or Six Sevelamer 800 mg sachets of powder for oral suspension) per day based on clinical needs and serum phosphorus level. Sevelamer Carbonate tablet or suspension must be taken three times per day with meals.

For patients previously on phosphate binders (Sevelamer Hydrochloride or calcium based), Sevelamer Carbonate should be given on a gram for gram basis with monitoring of serum phosphorus levels to ensure optimal daily doses.

Titration and Maintenance: Serum phosphorus levels must be monitored and the dose of Sevelamer Carbonate titrated every 2-4 weeks until an acceptable serum phosphorus level is reached, with regular monitoring thereafter. Patients taking Sevelamer Carbonate should adhere to their prescribed diets. In clinical practice, treatment will be continuous based on the need to control serum phosphorus levels and the daily dose is expected to be an average of approximately 6 g per day.

Paediatric population: The safety and efficacy of Sevelamer Carbonate has not been established in children below the age of 18 years. Sevelamer Carbonate is not recommended in children below the age of 18 years.

Method of administration for Sevelamer Carbonate tablet: Tablets should be swallowed intact and should not be crushed, chewed, or broken into pieces prior to administration.

Method of administration for Sevelamer Carbonate powder for oral suspension: Each sachet of 800 mg of powder is to be dispersed in 30 ml or 6 teaspoons of water prior to administration. The suspension should be ingested within 30 minutes after being prepared.

Drug interactions: Interaction studies have not been conducted in patients on dialysis. In interaction studies in healthy volunteers, Sevelamer Hydrochloride, which contains the same active moiety as Sevelamer Carbonate, decreased the bioavailability of ciprofloxacin by approximately 50% when co-administered with Sevelamer Hydrochloride in a single dose study. Consequently, Sevelamer Carbonate should not be taken simultaneously with ciprofloxacin. Reduced levels of ciclosporin, mycophenolate mofetil and tacrolimus have been reported in transplant patients when co-administered with Sevelamer Hydrochloride without any clinical consequences (i.e graft rejection). The possibility of an interaction cannot be excluded and a close monitoring of blood concentrations of ciclosporin, mycophenolate mofetil and tacrolimus should be considered during the use of combination and after its withdrawal. Very rare cases of hypothyroidism have been reported in patients co-administered Sevelamer Hydrochloride, which contains the same active moiety as Sevelamer Carbonate, and levothyroxine. Closer monitoring of thyroid stimulating hormone (TSH) levels is therefore recommended in patients receiving Sevelamer Carbonate and levothyroxine. Patients taking anti-arrhythmic medicinal products for the control of arrhythmias and anti-seizure medicinal products for the control of seizure disorders were excluded from clinical trials. Caution should be exercised when prescribing Sevelamer Carbonate to patients also taking these medicinal products. In interaction studies in healthy volunteers, Sevelamer Hydrochloride, which contains the same active moiety as Sevelamer Carbonate, had no effect on the bioavailability of digoxin, warfarin, enalapril or metoprolol. Sevelamer Carbonate is not absorbed and may affect the bioavailability of other medicinal products. When administering any medicinal product where a reduction in the bioavailability could have a clinically significant effect on safety or efficacy, the medicinal product should be administered at least one hour before or three hours after Sevelamer Carbonate, or the physician should consider monitoring blood levels.

Sevelamer Carbonate is contraindicated in patients with bowel obstruction. Sevelamer Carbonate is contraindicated in patients with known hypersensitivity to sevelamer carbonate, sevelamer hydrochloride, or to any of the excipients.

Sevelamer carbonate is not absorbed systemically following oral administration and maternal use is not expected to result in fetal exposure to the drug. Clinical Considerations Sevelamer carbonate may decrease serum levels of fat soluble vitamins and folic acid in pregnant women.

Sevelamer carbonate is not absorbed systemically by the mother following oral administration, and breastfeeding is not expected to result in exposure of the child to Sevelamer carbonate. Clinical Considerations Sevelamer carbonate may decrease serum levels of fat soluble vitamins and folic acid in pregnant women.

Pediatric Use: The safety and efficacy of Sevelamer Carbonate in lowering serum phosphorus levels was studied in patients 6 years of age and older with CKD. In this study, Sevelamer Carbonate was apparently less effective in children with a low baseline serum phosphorus, which described children < 13 years of age and children not on dialysis. Given its mechanism of action, Sevelamer Carbonate is expected to be effective in lowering serum phosphorus levels in pediatric patients with CKD. Most adverse events that were reported as related, or possibly related, to sevelamer carbonate were gastrointestinal in nature. No new risks or safety signals were identified with the use of sevelamer carbonate in the trial. Sevelamer Carbonate has not been studied in pediatric patients below 6 years of age.

Geriatric Use: Clinical studies of Sevelamer Carbonate did not include sufficient numbers of subjects aged 65 and over to determine whether they respond differently from younger subjects. Other reported clinical experience has not identified differences in responses between the elderly and younger patients. In general, dose selection for an elderly patient should be cautious, usually starting at the low end of the dosing range.

Drugs for reduction of serum phosphorus in patients with ESRD

In CKD patients on dialysis, the maximum dose studied was 14 grams of sevelamer carbonate and 13 grams of sevelamer hydrochloride. There are no reports of overdosage with sevelamer carbonate or sevelamer hydrochloride in patients. Since sevelamer is not absorbed, the risk of systemic toxicity is low.

Store in a cool and dry place, protected from light.