Bronchodilatory effects of aclidinium bromide, a long-acting muscarinic antagonist, in COPD patients.

BACKGROUND: Aclidinium bromide is a novel, long-acting, inhaled muscarinic antagonist bronchodilator currently in Phase III clinical development for the treatment of chronic obstructive pulmonary disease (COPD). This study evaluated the pharmacodynamics, pharmacokinetics, safety and tolerability of ascending doses of aclidinium bromide in patients with COPD. METHODS: This double-blind, randomised, placebo-controlled, crossover study was conducted in patients with moderate to severe COPD (forced expiratory volume in 1s [FEV(1)] <65% predicted). Patients were randomly assigned to one of four treatment sequences of aclidinium bromide 100, 300, 900microg and placebo with a washout period between doses. The primary outcome was area under the FEV(1) curve over the 0-24h time interval. RESULTS: Seventeen patients with COPD were studied. Mean FEV(1) over 24h was 1.583L for placebo, and 1.727L, 1.793L and 1.815L for aclidinium bromide 100, 300 and 900microg, respectively (p<0.001 vs. placebo, all doses). Significant changes from baseline in FEV(1) were detected 15min post-dose for aclidinium bromide 300 and 900microg, with a peak effect 2h post-dose (all doses). Aclidinium bromide was undetected in plasma. The majority of adverse events was unrelated to study medication and did not result in discontinuation. CONCLUSION: Aclidinium bromide 100-900microg produced sustained bronchodilation over 24h in patients with COPD.

Dual tachykinin NK1/NK2 antagonist DNK333 inhibits neurokinin A-induced bronchoconstriction in asthma patients.

Inhalation of neurokinin A (NKA) causes bronchoconstriction in patients with asthma. In vitro both tachykinin NK1 and NK2 receptors can mediate airway contraction. In this study the authors examined the effects of a single dose of the dual tachykinin NK1/NK2 receptor antagonist, DNK333, on NKA-induced bronchoconstriction in asthma. A total of 19 male adults with mild asthma completed a randomised, double-blind, placebo-controlled crossover trial. Increasing concentrations of NKA (3.3x10(-9) to 1.0x10(-6) mol x mLP(-1)) were inhaled at 1 and 10 h intervals after a single oral dosing with either DNK333 (100 mg) or a placebo. It was observed that DNK333 did not affect baseline lung function but did protect against NKA-induced bronchoconstriction in those patients. The mean log10 provocative concentration causing a 20% fall in forced expiratory volume in one second for NKA was -5.6 log10 mol x mL(-1) at 1 h after DNK333 treatment and -6.8 log10 mol x mL(-1) after placebo. This was equivalent to a difference of 4.08 doubling doses, which decreased to a difference of 0.90 doubling doses 10 h after treatment. The results shown in this report indicate that DNK333 blocks neurokinin A-induced bronchoconstriction in patients with asthma.