Risks of developing kidney failure, calcium deficiency from zoledronic acid are extremely rare

The risks of developing kidney failure and a calcium deficiency from the popular osteoporosis drug zoledronic acid are extremely rare, according to researchers at Loyola University Health System (LUHS). These findings were presented earlier this month at the American Society for Bone and Mineral Research's annual meeting.

"Osteoporosis is a growing problem in this country," said Laurae Hicks, first author and Stritch School of Medicine medical student. "These findings are valuable for the millions of Americans who suffer from osteoporosis and are considering their treatment options."

Zoledronic acid is commonly used to treat osteoporosis. The treatment strengthens bones by increasing the process by which bone is broken down and replaced with new bone tissue. While this medication is effective at preventing and treating osteoporosis, potential side effects include kidney failure and hypocalcemia.

Kidney failure occurs when the kidneys fail to adequately filter waste products from the blood while hypocalcemia is characterized by low calcium levels in the blood. This condition can lead to a variety of symptoms, including weakness, muscle cramps, excessive nervousness, headaches or uncontrollable twitching and cramping in certain muscles.

"This study helped us determine the severity and prevalence of these side effects," said Pauline Camacho, MD, study investigator and director of the Loyola University Osteoporosis and Metabolic Bone Disease Center. "This will help us assess which patients are good candidates for this treatment."

Researchers studied 237 patients before and after they received injections of zoledronic acid. They found that a slight and clinically insignificant decline in calcium levels may be seen after the first infusion, but these effects appear to be transient. The findings apply only to individuals with normal vitamin D levels and kidney function prior to infusion and cannot be generalized to those with renal insufficiency and existing calcium and vitamin D deficiencies.