UF Health MedMatters

UF Health’s NIH-Sponsored Trial Seeks to Solve Painful Kidney Stones

A half million people visit emergency rooms each year with kidney stone problems, and today’s treatments aren’t ideal. UF Health is being entrusted by the National Institutes of Health to find a better solution for those suffering from a condition that can be severely painful. woman with kidney stone

Benjamin Canales, MD, MPH, of the UF Department of Urology, along with four other colleagues from different departments, received NIH funding for the 18-month “POuND OUT” trial, which launched in the spring and is recruiting participants. It is one of only a few NIH-sponsored drug trials aimed at preventing uric acid kidney stones.

Uric acid is a compound in all urine. It accounts for about 10% of kidney stones from a specific population whose urine pH is too acidic and results in the compound crystalizing. This UF Health study will test two existing drugs that may slow the growth of these stones or prevent them from forming.

The study is significant because it is focused on the root cause of kidney stones and aims to improve the current standard of care, which is to prescribe six to 10 doses of bicarbonate pills a day for the rest of the patient’s life.

“A lot of uric acid patients struggle to maintain that regimen long term,” said Canales, an associate professor and director of research at the UF College of Medicine’s department of urology, who is facilitating the clinical trial. “It seems that we are masking the problem with a bicarbonate instead of trying to treat the underlying causes, which are obesity and diabetes.”

The two drugs being used to address obesity, insulin resistance and overly acidic urine are phentermine and topiramate. Phentermine is the most-used weight loss drug in the United States, a stimulant that increases patients’ metabolism to burn more energy and lose weight. Topiramate helps to calm neurons in the brain to reduce cravings and combat binge eating disorders, while also increasing bicarbonate from the kidneys into the urine.

The primary goal of these drugs is to prevent the growth of uric acid stones and the formation of new ones. Meanwhile, the trial will explore whether the drugs can be used to support lifestyle changes that reduce the amount of acid secreted by the kidney.

Canales is hoping the trial yields answers for a population that would benefit both physically and psychologically if these kidney stones were averted.

“Urologists have made great advancements in surgically removing stones, but where we fail as clinicians is preventing them,” Canales said. “Once a patient has one stone, they are likely to recur, and then it becomes a lifelong process of passing stones and living in fear of getting another.”

The R21 grant was funded through the NIH Institute of Diabetes and Digestive and Kidney Diseases, or NIDDK, section. The UF Department of Urology proved itself as an ideal host for this trial for several reasons. In addition to being ranked as one of the top urology programs in the nation for 2021-22 by U.S. News & World Report, the department has a large patient base that provides a wealth of treatment experience and potential participants.

Recruitment for this trial is ongoing for anyone ages 18-75 who has pre-diabetes or Type 2 diabetes and uric acid stones. Participants will also be compensated for their efforts, courtesy of the NIH.

About UF Health Shands Hospital

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University of Florida Health Shands Hospital has been recognized among the nation’s best hospitals in seven adult medical specialties. Overall, UF Health Shands Hospital was recognized as one of the best hospitals in Florida. In addition to being ranked among the nation’s top 50 hospitals in seven specialties, UF Health Shands Hospital also was listed as “high performing” in seven specialties, including abdominal aortic aneurysm repair, colon cancer surgery, COPD, heart failure, lung cancer surgery, neurology & neurosurgery and orthopaedics.