Medical management to prevent recurrent nephrolithiasis in adults: a systematic review for an American College of Physicians Clinical Guideline.
Level 1 - systematic review of randomized trials
Systematic review of 28 randomized controlled trials
PubMed 23546565 · doi:10.7326/0003-4819-158-7-201304020-00005
What was done
Systematic review of MEDLINE, Cochrane, and other databases through September 2012 searching for English-language randomized controlled trials (RCTs) evaluating interventions to prevent recurrent kidney stones. Data extraction was performed by one reviewer and checked by a second, with two reviewers independently rating study quality and grading evidence strength across 28 included RCTs.
What was found
In patients with 1 past calcium stone: - Increased fluid intake reduced composite stone recurrence risk compared with no treatment (RR 0.45 [95% CI, 0.24 to 0.84]; low-strength evidence). - Reducing soft-drink consumption decreased recurrent symptomatic stone risk (RR 0.83 [95% CI, 0.71 to 0.98]; low-strength evidence). In patients with multiple past calcium stones (most receiving increased fluid intake): - Thiazides reduced composite stone recurrence risk (RR 0.52 [95% CI, 0.39 to 0.69]; moderate-strength evidence). - Citrates reduced composite stone recurrence risk (RR 0.25 [95% CI, 0.14 to 0.44]; moderate-strength evidence). - Allopurinol reduced composite stone recurrence risk (RR 0.59 [95% CI, 0.42 to 0.84]; moderate-strength evidence), with benefit limited to baseline hyperuricemia or hyperuricosuria. - Neither citrate nor allopurinol combined with thiazide was superior to thiazide alone (low-strength evidence). - Withdrawals were frequent among non-fluid dietary interventions and higher with thiazides and citrates than controls. Adverse event reporting across trials was poor.
Why it matters
This review establishes that fluid intake alone cuts recurrence risk after an initial stone, whereas patients with recurrent calcium stones benefit from adding thiazides, citrates, or targeted allopurinol.
Limits
Review restricted to English-language trials. Most participants had idiopathic calcium stones, limiting applicability to other stone compositions. Nearly all studies evaluated composite recurrence outcomes that included asymptomatic stones rather than symptomatic episodes alone. Adverse events were poorly reported, and evidence strength for fluid, dietary, and combination regimens was low.
Cited by
- supports Maintaining a daily fluid intake of at least 2.5 liters dilutes urine sufficiently to prevent kidney stone formation.