<p>In patients with normal liver function, erythromycin concentrates in the liver and is then excreted in the bile.<sup class="text-reference-group"><a class="reference-popover-link" data-content="MedSafe NZ: ERA (erythromycin stearate) oral filmtabs" href="#reference-L7270">22</a></sup>Under 5% of the orally administered dose of erythromycin is found excreted in the urine.<sup class="text-reference-group"><a class="reference-popover-link" data-content="MedSafe NZ: ERA (erythromycin stearate) oral filmtabs" href="#reference-L7270">22</a>,<a class="reference-popover-link" data-content="Kavi J, Webberley JM, Andrews JM, Wise R: A comparison of the pharmacokinetics and tissue penetration of spiramycin and erythromycin. J Antimicrob Chemother. 1988 Jul;22 Suppl B:105-10. doi: 10.1093/jac/22.supplement_b.105. (PubMed ID 3182434)" href="#reference-A180607">19</a></sup> A high percentage of absorbed erythromycin is not accounted for, but is likely metabolized.<sup class="text-reference-group"><a class="reference-popover-link" data-content="MedSafe NZ: ERA (erythromycin stearate) oral filmtabs" href="#reference-L7270">22</a></sup></p>