Phentermine/Topiramate and Uric Acid Stones

PHENTERMINE/TOPIRAMATE reduced uric acid stone volume among patients with obesity and diabetes in an 18-month open-label feasibility trial, with the intervention group also achieving greater weight loss and changes in urinary risk factors.

Nineteen participants with obesity, diabetes mellitus , normal renal function, urine pH below 5.8, and stones comprising at least 80% uric acid were randomised in a 2:1 ratio to phentermine 18.75 mg/topiramate 100 mg or pragmatic controls.

The prospective study used dose escalation and assessed change in computed tomography stone volume as its primary outcome. Secondary outcomes included medication adherence, safety, anthropometric measures, laboratory results, and body composition.

Fifteen participants completed the study, with 73% pill adherence and no serious adverse events. In the intention-to-treat analysis, stone volume decreased by 52% in the intervention group compared with an 8.6% increase in controls (P=0.10).