Kidney stones can be excruciatingly painful and dangerous, but relief may be on the way. A new University of Florida Health clinical trial will test two existing drugs that may slow the growth of these stones or prevent them from forming.
The UF Department of Urology is recruiting participants for the 18-month “POuND OUT” study, one of only a few National Institutes of Health-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. The current standard of care for a patient with kidney stones is to prescribe six to 10 doses of bicarbonate pills a day for the rest of the patient’s life, but adhering to that treatment can be daunting.
“A lot of uric acid patients struggle to maintain that regimen long term,” said Benjamin Canales, M.D., M.P.H., an associate professor and director of research at 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 study will use two drugs, phentermine and topiramate, to treat obesity, insulin resistance and overly acidic urine, with a primary goal of preventing the growth of uric acid stones and the formation of new ones. The trial will explore whether the drugs can be used to support lifestyle changes that reduce the amount of acid secreted by the kidney.
“Urologists have made great advancements in surgically removing stones, but where we fail as clinicians is preventing them. 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,” Canales said.
Phentermine is a stimulant that raises patients’ metabolism to burn more energy and lose weight. It is the most used weight-loss drug in the country. Topiramate helps to calm neurons in the brain to reduce cravings and combat binge eating disorders. It also increases bicarbonate from the kidneys into the urine.
Recruitment for this trial is undergoing for anyone age 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.
“We are interested in talking to anyone and everyone who thinks they might qualify to help contribute to the body of knowledge to help us improve health care and outcomes for kidney stone patients,” Canales said.
The trial will include 30 participants, 20 of whom will be randomly assigned to receive the drugs. The remaining 10 will remain on their standard medication regimen as a control group. Both groups will have access to a registered dietitian and will participate in five visits to the UF Clinical Research Center to record their vitals and other data.
A CT scan will also be conducted at the beginning and end of the trial for stone analysis. This requires collaborative efforts between John Marks, D.H.Sc., CCRP, the clinical research coordinator for the trial, and the radiology department, the nursing staff at the Clinical Research Center and the UF Health medical labs to collect and verify data and to schedule labwork and scans.
Marks said the UF urology department, in addition to being recognized as a Top 20 urology program in the nation, is the ideal host for this trial because its large patient base provides a wealth of treatment experience and potential participants.
Canales said he hopes the trial, sponsored by the National Institute of Diabetes and Digestive and Kidney Diseases, will lead to collaboration for a multicenter clinical trial within a year or two.