Treatment with phosphate binders significantly lowered patients’ urinary phosphorus levels, moderately lowered their blood phosphorus levels, and slowed progression of a parathyroid disorder that is a common complication of CKD, while treatment with placebo did not. Despite these positive effects, phosphate binders did not have any effect on the blood levels of a hormone that regulates phosphate excretion in the urine, and the drugs caused calcium build-up in blood vessels, which can lead to heart problems. Heart disease is the leading cause of death in patients with CKD.
These findings call into question the safety and effectiveness of phosphate binders in patients with CKD.
“While we continue to believe that serum, or blood, phosphorus is a key component of the increased cardiovascular risk associated with kidney disease, our results suggest the use of the currently approved phosphate binding drugs does not result in substantial reductions in serum phosphorus and may be associated with harm in this population,” Block said. “Future clinical trials should be conducted in all populations with adequate placebo controls and should address alternative or complementary methods to reduce serum phosphorus,” he added.