Dietary changes and medications may help prevent recurrent nephrolithiasis

A systematic review of randomized and nonrandomized studies suggests that increased fluid intake, dietary modification, and selected pharmacologic therapies may reduce recurrence of nephrolithiasis in adults. The analysis, published in Annals of Internal Medicine, also highlights a notable absence of evidence supporting surveillance imaging as a preventive strategy.¹

For practicing urologists, the findings reinforce current guideline-based approaches emphasizing lifestyle modification and targeted pharmacotherapy, while underscoring persistent evidence gaps—particularly regarding imaging and pediatric populations.

The review was conducted by investigators from the RTI–University of North Carolina Evidence-Based Practice Center. They evaluated 31 studies, including 26 randomized controlled trials and 5 nonrandomized studies, assessing interventions to prevent recurrent kidney stones. Most studies enrolled nonpregnant adult populations, with only 3 pediatric studies identified.

Across studies focused on calcium oxalate or calcium phosphate stones, several interventions were associated with reduced recurrence risk. These included increased water intake; diets characterized by normal-to-high calcium intake combined with reduced sodium and protein; and pharmacologic therapies such as thiazide diuretics, alkali treatment (eg, potassium citrate), and allopurinol. However, the strength of evidence supporting these interventions was graded as low (for at least a small benefit), and the pharmacologic interventions were notably downgraded from moderate to low strength of evidence in this updated review.

The review also found no meaningful difference between selective (metabolic evaluation–guided) and empirical pharmacotherapy approaches, again based on low-strength evidence. Acetohydroxamic acid demonstrated potential to reduce stone growth in infection-related nephrolithiasis but was associated with increased adverse events and lacked sufficient data on recurrence prevention.

Lemon juice as a dietary alkali therapy was associated with both a small benefit and increased minor adverse events. The review also showed insufficient evidence for febuxostat, a uric acid-lowering agent.

Notably, no included studies evaluated surveillance imaging strategies for preventing recurrence, representing a significant gap in the literature.

Current guidelines from the American Urological Association recommend increased fluid intake to achieve urine volumes of at least 2.5 L per day, dietary sodium restriction, and moderation of animal protein intake, alongside pharmacologic therapy tailored to metabolic abnormalities.² The present review largely aligns with these recommendations but highlights the limited quality of supporting evidence.

Importantly, the absence of evidence for surveillance imaging does not necessarily imply lack of benefit, but rather reflects a gap in prospective evaluation. Given the increasing use of imaging in follow-up, this represents an area in need of further study.

The authors acknowledged several limitations, including that most studies were rated as having high risk of bias, and many were conducted using older imaging modalities or outcome definitions that may not reflect current standards. Additionally, studies with fewer than 30 participants per group and non-English publications were excluded, which may limit generalizability. Evidence in pediatric populations was notably sparse, and no studies evaluated surveillance imaging strategies.

Ongoing trials, including behavioral interventions to improve hydration adherence and comparative pharmacotherapy studies, may help address some of these gaps. Future research priorities include adequately powered randomized trials, standardized outcome definitions, and head-to-head comparisons of dietary and pharmacologic strategies.

REFERENCES
1. Asher GN, Viprakasit DP, Aymes SE, et al. Prevention of Recurrent Nephrolithiasis in Adults and Children: A Systematic Review. Ann Intern Med. 2026. doi:10.7326/ANNALS-25-04452.

2. Medical Management of Kidney Stones (2019). American Urological Association. Accessed March 24, 2026. https://www.auanet.org/guidelines-and-quality/guidelines/kidney-stones-medical-mangement-guideline