Clinical disposition, metabolism and in vitro drug–drug interaction properties of omadacycline

Abstract1. Absorption, distribution, metabolism, transport and elimination properties of omadacycline, an aminomethylcycline antibiotic, were investigated in vitro and in a study in healthy male subjects.2. Omadacycline was metabolically stable in human liver microsomes and hepatocytes and did not inhibit or induce any of the nine cytochrome P450 or five transporters tested. Omadacycline was a substrate of P-glycoprotein, but not of the other transporters.3. Omadacycline metabolic stability was confirmed in six healthy male subjects who received a single 300 mg oral dose of [14C]-omadacycline (36.6 μCi). Absorption was rapid with peak radioactivity (∼610 ngEq/mL) between 1–4 h in plasma or blood. The AUClast of plasma radioactivity (only quantifiable to 8 h due to low radioactivity) was 3096 ngEq h/mL and apparent terminal half-life was 11.1 h. Unchanged omadacycline reached peak plasma concentrations (∼563 ng/mL) between 1–4 h. Apparent plasma half-life was 17.6 h with biphasic elimination. Plasma exposu...