<p>The plasma elimination half-life is approximately 3.0 to 4.5 hours following single and multiple oral doses. The half-life may slightly increase with dose and the extent of hepatic impairment.<sup class="text-reference-group"><a class="reference-popover-link" data-content="CARDIZEM® LA (diltiazem hydrochloride) extended-release tablets - FDA Label" href="#reference-L10556">12</a></sup> The apparent elimination half-life for diltiazem as extended-release tablets after single or multiple dosing is 6 to 9 hours.<sup class="text-reference-group"><a class="reference-popover-link" data-content="CARDIZEM® LA (diltiazem hydrochloride) extended-release tablets - FDA Label" href="#reference-L10556">12</a></sup> The plasma elimination half-life is approximately 3.4 hours following administration of a single intravenous injection.<sup class="text-reference-group"><a class="reference-popover-link" data-content="Diltiazem Hydrochloride Injection Label - Bedford Laboratories" href="#reference-L6292">10</a></sup> The elimination half-lives of pharmacologically active metabolites are longer than that of diltiazem.<sup class="text-reference-group"><a class="reference-popover-link" data-content="Yeung PK, Prescott C, Haddad C, Montague TJ, McGregor C, Quilliam MA, Xei M, Li R, Farmer P, Klassen GA: Pharmacokinetics and metabolism of diltiazem in healthy males and females following a single oral dose. Eur J Drug Metab Pharmacokinet. 1993 Apr-Jun;18(2):199-206. doi: 10.1007/BF03188796. (PubMed ID 8243504)" href="#reference-A178516">6</a></sup></p>