The mechanism of action (MoA) of SPIRIVA® Respimat®
‘Acetylcholine in the airways and the role SPIRIVA® Respimat® (tiotropium) in asthma’ illustrates the mechanism of action (mode of action or MoA) of SPIRIVA® Respimat®, an inhaled long-acting anticholinergic medication, for the treatment of symptomatic asthma.
Asthma – the role of acetylcholine
Released from parasympathetic nerves, acetylcholine regulates bronchoconstriction and mucus secretion and clearance and is known to play a significant role in the pathophysiology of asthma.1,2 Acetylcholine modulates inflammation increases airway tone, contracts bronchial smooth muscle, and leads to mucus secretion and vasodilation. 1 The muscarinic M3 receptor is the primary subtype responsible for bronchial and tracheal smooth muscle contraction.2
How does SPIRIVA® Respimat® work in asthma?
SPIRIVA® Respimat® competitively and reversibly binds to M3 muscarinic receptors in bronchial smooth muscles antagonising the cholinergic (bronchoconstrictive) effects of acetylcholine, resulting in bronchial smooth muscle relaxation.3
Tiotropium bromide is a long-acting muscarinic antagonist (LAMA).3 It antagonises the effect of acetylcholine, which is the main neurotransmitter in the parasympathetic nervous system of the airways.4 Acetylcholine binds to muscarinic receptors. These receptors mediate bronchoconstriction and the secretion of mucus.1 Tiotropium bromide binds competitively and reversibly to M3 receptors, which results in relaxation of the bronchial smooth musculature3 and bronchodilation.
Acetylcholine regulates bronchoconstriction and mucus secretion and is known to play a significant role in the pathophysiology of asthma. Tiotropium bromide is a long-acting muscarinic antagonist.1 It antagonises the effect of acetylcholine.
Tiotropium bromide binds competitively and reversibly to M3 receptors, which results in relaxation of the bronchial smooth musculature1 and bronchodilation.
Onset and duration of action
Tiotropium Respimat® is a once daily maintenance bronchodilator for asthma and should not be used for immediate relief of breathing problems/ sudden breathing problems (i.e., as a rescue medication).3
However, there were numerical improvements in lung function starting at Day 1 seen at 30 minutes5, with statistical improvements at one hour.5
The effects were maintained for 24 hours.5