<p><strong>In adult and pediatric patients with recurrent calcium stones and low or relatively low urinary citrate, clinicians should offer alkali therapy. (<em>Expert Opinion</em>)</strong></p>
Discussion
Discussion
<p>Urinary citrate is an important inhibitor of calcium stone formation and growth, and a significant proportion of patients with recurrent calcium stones exhibit lower urinary citrate excretion.<sup>182</sup> In patients with calcium stones and lower urinary citrate excretion, alkali therapy raised urinary citrate and reduced recurrent stone formation in RCTs<sup>60, 183</sup> and observational studies.<sup>184-186</sup> In the majority of these studies, the form of alkali therapy used was potassium citrate at doses of 30-80 mEq/day in adults and 1 mEq/kg of body weight/day in pediatric patients<sup>49</sup> which significantly raised urinary citrate excretion. In general, potassium-based preparations are preferred over sodium-based alternatives due to the potential for sodium-induced urinary calcium excretion<sup>187</sup> and the greater solubility of potassium urate compared with sodium urate. Low potassium preparations may be considered to achieve therapeutic urinary pH and/or citrate levels in patients with hyperkalemia or who develop hyperkalemia on potassium-based preparations. Citric acid-based preparations are not recommended as a source of alkali since they do not deliver an alkali load and do not raise urinary citrate or pH.<sup>188</sup> During alkali citrate therapy, care should be taken not to excessively raise urinary pH as this may increase the saturation of urine with respect to calcium phosphate.<sup>189</sup> Please refer to <strong>Statement 36</strong> regarding the use of over-the-counter alkali products to raise urine citrate.</p>