Effect of potassium citrate supplement on stone recurrence before or after lithotripsy: systematic review and meta-analysis

This meta-analysis summarizes the available evidence on the effectiveness of citrate supplement for preventing the recurrence of nephrolithiasis in patients undergoing extracorporeal shock wave lithotripsy (SWL). Electronic searches were conducted using Medline-PubMed, Web of Science, Embase, BVS (Scielo, Lilacs), and Google Scholar literature databases. The authors worked in pairs to select studies that met the following criteria: randomized controlled trials that were conducted in adults and assessed the effect of potassium citrate supplement before or after SWL therapy for urolithiasis. Our primary aim was to asses the stone-free rate among the groups included in the studies. Fixed effect was used in the meta-analysis with 95% confidence interval (95% CI). Heterogeneity was analyzed by the I 2 value. A total of 2505 references were initially selected. Of those, four were subjected to meta-analysis contributing five samples. These four studies included 374 participants who were followed for a period of 12 months after SWL. Mean potassium citrate dosage was approximately 55 mEq/day (18 mmol). The results showed that citrate supplement significantly protected against the recurrence of nephrolithiasis during 1 year after SWL [RR; 95% CI 0.21 (0.13, 0.31)]. The heterogeneity was not significant across the analyzed studies ( p = 0.224). The quality of the analyzed studies was generally low. The available evidence shows that citrate supplement effectively reduces the recurrence of nephrolithiasis in patients undergoing SWL. However, statistical analysis of a larger trial conducted with methodological rigor is warranted.