sevelamer hydrochloride

Clinical summary

Indications and usage 1. INDICATIONS AND USAGE Sevelamer hydrochloride tablets are indicated for the control of serum phosphorus in patients with chronic kidney disease (CKD) on dialysis. The safety and efficacy of sevelamer hydrochloride tablets in CKD patients who are not on dialysis have not been studied. • Sevelamer hydrochloride tablets are a phosphate binder indicated for the control of serum phosphorus in patients with chronic kidney disease on dialysis. ( 1 ) Dosage and administration 2. DOSAGE AND ADMINISTRATION Patients Not Taking a Phosphate Binder . The recommended starting dose of sevelamer hydrochloride tablets is 800 to 1600 mg, which can be administered as one or two 800 mg sevelamer hydrochloride tablets or two to four 400 mg sevelamer hydrochloride tablets, with meals based on serum phosphorus level. Table 1 provides recommended starting doses of sevelamer hydrochloride tablets for patients not taking a phosphate binder. Table 1: Starting Dose for Dialysis Patients Not Taking a Phosphate Binder Serum Phosphorus Sevelamer Hydrochloride Tablets 800 mg Sevelamer Hydrochloride Tablets 400 mg >5.5 and 5.5 mg/dL Increase 1 tablet per meal at 2-week intervals 3.5 to 5.5 mg/dL Maintain current dose <3.5 mg/dL Decrease 1 tablet per meal • Starting dose is one or two 800 mg or two to four 400 mg tablets three times per day with meals. ( 2 ) • Adjust by one tablet per meal in two-week intervals as needed to obtain serum phosphorus target (3.5 to 5.5 mg/dL). ( 2 ) Warnings and cautions 5. WARNINGS AND PRECAUTIONS • Serious cases of dysphagia, bowel obstruction, bleeding gastrointestinal ulcers, colitis, ulceration, necrosis, and perforation have been associated with sevelamer use, some requiring hospitalization and surgery. ( 5.1 ) 5.1 Gastrointestinal Adverse Events Patients with dysphagia, swallowing disorders, severe gastrointestinal (GI) motility disorders, including severe constipation, or major GI tract surgery were not included in the sevelamer hydrochloride clinical studies. Dysphagia and esophageal tablet retention have been reported in association with use of sevelamer tablets, some requiring hospitalization and intervention. Consider using sevelamer suspension in patients with a history of swallowing disorders. Cases of bowel obstruction, bleeding gastrointestinal ulcers, colitis, ulceration, necrosis, and perforation have also been reported with sevelamer use [see Adverse Reactions (6.2)] . Inflammatory disorders may resolve upon sevelamer hydrochloride discontinuation. Treatment with sevelamer hydrochloride should be re-evaluated in patients who develop severe gastrointestinal symptoms. 5.2 Monitor Serum Chemistries Bicarbonate and chloride levels should be monitored. 5.3 Monitor for Reduced Vitamins D, E, K (clotting factors) and Folic Acid Levels In preclinical studies in rats and dogs, sevelamer hydrochloride reduced vitamins D, E, and K (coagulation parameters) and folic acid levels at doses of 6 to 10 times the recommended human dose. In short-term clinical trials, there was no evidence of reduction in serum levels of vitamins. However, in a one-year clinical trial, 25-hydroxyvitamin D (normal range 10 to 55 ng/mL) fell from 39 ± 22 ng/mL to 34 ± 22 ng/mL (p<0.01) with sevelamer hydrochloride treatment. Most (approximately 75%) patients in sevelamer hydrochloride clinical trials received vitamin supplements, which is typical of patients on dialysis. Drug interactions 7. DRUG INTERACTIONS There are no empirical data on avoiding drug interactions between sevelamer hydrochloride and most concomitant oral drugs. For oral medication where a reduction in the bioavailability of that medication would have a clinically significant effect on its safety or efficacy (e.g., cyclosporine, tacrolimus, levothyroxine), consider separation of the timing of the administration of the two drugs [see Clinical Pharmacology ( 12.3 )] . The duration of separation depends upon the absorption characteristics of the medication concomitantly administered, such as the time to reach peak systemic levels and whether the drug is an immediate-release or an extended-release product. Where possible monitor clinical responses or blood levels of concomitant drugs that have a narrow therapeutic range. Table 4: Sevelamer Drug Interactions Oral drugs for which sevelamer did not alter the pharmacokinetics when administered concomitantly Digoxin Enalapril Iron Metoprolol Warfarin Oral drugs that have demonstrated interaction with sevelamer and are to be dosed separately from sevelamer hydrochloride Dosing Recommendations Ciprofloxacin Take at least 2 hours before or 6 hours after sevelamer Mycophenolate mofetil Take at least 2 hours before sevelamer • When clinically significant drug interactions are expected, separate the timing of administration and monitor clinical responses or blood levels of the concomitant medication. ( 7 ) • Sevelamer did not alter the pharmacokinetics of digoxin, enalapril, iron, metoprolol, and wa