<p><strong>In adult and pediatric patients with cystine stones, clinicians should offer alkali therapy to raise urinary pH. (<em>Expert Opinion</em>)</strong></p>
<p></p>
Discussion
Discussion
<p>The solubility of cystine in urine is pH-dependent, and urine alkalinization is a cornerstone in the management of cystine stones. In patients with cystine stones, alkali therapy with potassium citrate is preferred over sodium alkali (sodium citrate or bicarbonate) since cystine excretion increases with sodium excretion.<sup>218</sup> In addition to the recommendations to increase fluid intake and reduce sodium intake discussed in <strong>Statements 28 and 29</strong> above, the recommended target urine pH is between 7.0-7.5 in order to increase cystine solubility to >250 mg/L without excessively increasing the risk of calcium phosphate precipitation.</p>