# A Fresh Look at Oral Chemolysis for Non-Symptomatic Kidney Stones—Comparative Research of Potassium Citrate and Allopurinol Combination—Is Treatment Possible Without Stone Analysis?

## TL;DR

This study compares potassium citrate and a combination with allopurinol for dissolving kidney stones without needing detailed stone analysis.

## Contribution

The study shows potassium citrate can be used effectively without stone analysis or allopurinol.

## Key findings

- Potassium citrate significantly reduced kidney stone size without needing advanced analysis.
- Adding allopurinol to potassium citrate provided no additional benefit.
- Urine pH improved significantly in all patients after treatment.

## Abstract

Background/Objectives: To compare the results of oral chemolysis of non-opaque and semi-opaque kidney stones using potassium citrate (PS) and allopurinol + potassium citrate (ALPS) prospectively without advanced metabolic analysis. Methods: Between 2020 and 2022, 59 patients aged 19–60 years with non-obstructive, semi-opaque, and non-opaque kidney stones of 8–13 mm in size detected by non-contrast tomography were investigated, and oral chemolysis (potassium citrate 10 mEq 2 × 2, allopurinol 10 mEq 2 × 2) was initiated. Patients were divided into two groups, potassium citrate (PS) and allopurinol + potassium citrate (ALPS), according to the treatment to be received. The essential characteristics of the groups, monthly laboratory values throughout the process, and the stone size measured by non-contrast tomography at the initial presentation and the stone size after a mean of 9–10 months of treatment was recorded and compared. Results: The inferior calyx was the most common location. There were no statistically significant differences between the groups with regard to age, sex, size, location or side. Before treatment, the mean stone size was 11.01 ± 2.27 mm in the potassium citrate group and 11.1 ± 2.03 mm in the other group. Following treatment, both groups changed significantly, but did not differ statistically (p < 0.001) (p = 0.281). The mean urine pH of all patients changed considerably after treatment (p < 0.001). Conclusions: Potassium citrate-based urinary alkalisation can be started for non-opaque and semi-opaque kidney stones without metabolic analysis if the urine pH is appropriate. The combination of allopurinol with potassium citrate has no therapeutic advantage.