Sevelamer carbonate (Renvela – Genzyme), a buffered form of the anion-exchange resin sevelamer hydrochloride (Renagel – Genzyme),1 has been approved by the FDA for use in patients with chronic kidney disease on dialysis. According to the manufacturer, Renvela will replace Renagel, which has been shown to induce or exacerbate metabolic acidosis in patients on dialysis. Two randomized, crossover studies found the two sevelamer salts equivalent in their ability to lower serum phosphate.2,3 Patients taking the carbonate had higher serum bicarbonate concentrations and fewer gastrointestinal...

Most patients with end-stage renal disease develop hyperphosphatemia, which can lead to secondary hyperparathyroidism, vascular calcification, and cardiovascular mortality. The FDA has approved sucroferric oxyhydroxide (Velphoro – Fresenius Medical Care), a chewable phosphate binder, for treatment of hyperphosphatemia in patients with chronic kidney disease (CKD) on dialysis. It is the first iron-based phosphate binder to be approved for this indication.

Hyperphosphatemia in end-stage renal disease can lead to secondary hyperparathyroidism, renal osteodystrophy, metastatic calcification and cardiovascular mortality. addition to dietary restriction of phosphorus and hemodialysis, drugs that bind phosphates in the gut are usually needed as well. Aluminum hydroxide is no longer recommended for long-term use because of concerns about its toxicity.

The FDA has approved ferric citrate (Auryxia – Keryx), an oral phosphate binder, for treatment of hyperphosphatemia in patients with chronic kidney disease (CKD) on dialysis. It is the second iron-based phosphate binder to be approved in the US, and the first that causes significant systemic absorption of iron. Auryxia is not FDA-approved for treatment of iron deficiency anemia.

The FDA has approved the sodium/hydrogen exchanger 3 (NHE3) inhibitor tenapanor (Xphozah – Ardelyx) to reduce serum phosphorus in adults with chronic kidney disease (CKD) on dialysis as add-on therapy when phosphate binders are ineffective or as monotherapy when phosphate binders cannot be tolerated. Tenapanor is the first NHE3 inhibitor to be approved in the US for hyperphosphatemia. It was previously approved as Ibsrela to treat irritable bowel syndrome with constipation (IBS-C).

Primary hypothyroidism is usually the result of Hashimoto's (autoimmune) thyroiditis, thyroidectomy, or radioactive iodine therapy. Treatment of hypothyroidism with replacement doses of thyroid hormone is usually lifelong. Levothyroxine (LT4; synthetic thyroxine; Synthroid, and others) is the drug of choice.1