Systemic exposure to anticholinergics used for chronic obstructive pulmonary disease (COPD) may lead to side effects. This study assessed safety, tolerability, and pharmacokinetics of multiple doses of aclidinium bromide, a novel, long-acting antimuscarinic. Sixteen healthy participants received aclidinium bromide 200, 400, or 800 microg or placebo by dry-powder inhaler for 5 days, with > or =7 days washout. Aclidinium bromide and metabolite pharmacokinetics were assessed. Aclidinium bromide plasma levels were below the lower limit of quantification (LLOQ: 0.05 ng/mL) after 200 microg and in most participants after 400 microg. Plasma levels in all participants were below the LLOQ at all doses, including the highest dose, beyond 1 hour postdose. AUC(0-t) and C(max) at steady state were, respectively, 0.08 ng.h/mL and 0.12 ng/mL (aclidinium bromide), 0.40 ng.h/mL and 0.14 ng/mL (alcohol metabolite), and 13.47 ng.h/mL and 2.26 ng/mL (acid metabolite). The t(max) for aclidinium bromide 800 microg was 15 minutes (first kinetic time point). Adverse event frequency was comparable between treatment groups and placebo. The most commonly reported adverse events, probably treatment related, were coughing (n = 2) and dysphagia (n = 1); 94% of adverse events were mild. These data suggest a low systemic bioavailability and favorable safety profile for aclidinium bromide with repeated dosing for COPD.

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