ATC Group: R03BB Anticholinergics

Aclidinium is a competitive, selective muscarinic receptor antagonist (also known as an anticholinergic), with a longer residence time at the M3 receptors than the M2 receptors. M3 receptors mediate contraction of airway smooth muscle. Inhaled aclidinium acts locally in the lungs to antagonise M3 receptors of airway smooth muscle and induce bronchodilation.

Glycopyrronium is an inhaled long-acting muscarinic receptor antagonist (anticholinergic) for once-daily maintenance bronchodilator treatment of COPD. Glycopyrronium works by blocking the bronchoconstrictor action of acetylcholine on airway smooth muscle cells, thereby dilating the airways.

Ipratropium is a quaternary ammonium compound with anticholinergic (parasympatholytic) properties. Ipratropium appears to inhibit vagally mediated reflexes by antagonising the action of acetylcholine, the transmitter agent released from the vagus nerve. Anticholinergics prevent the increase in intracellular concentration of Ca++, which is caused by interaction of acetylcholine with the muscarinic receptor on bronchial smooth muscle. Ca++ release is mediated by the second messenger system consisting of IP3 (inositol triphosphate) and DAG (diacylglycerol).

Revefenacin is a long-acting muscarinic antagonist, which is often referred to as an anticholinergic. It has similar affinity to the subtypes of muscarinic receptors M1 to M5. In the airways, it exhibits pharmacological effects through inhibition of M3 receptor at the smooth muscle leading to bronchodilation. It is used for the maintenance treatment of patients with chronic obstructive pulmonary disease (COPD).

Tiotropium is a long-acting, specific, muscarinic receptor antagonist, in clinical medicine often called an anticholinergic. By binding to the muscarinic receptors in the bronchial smooth musculature, tiotropium inhibits the cholinergic (bronchoconstrictive) effects of acetylcholine, released from parasympathetic nerve endings.

Umeclidinium is a long acting muscarinic receptor antagonist (also referred to as an anticholinergic). It is a quinuclidine derivative that is a muscarinic receptor antagonist with activity across multiple muscarinic cholinergic receptor subtypes. Umeclidinium bromide exerts its bronchodilatory activity by competitively inhibiting the binding of acetylcholine with muscarinic cholinergic receptors on airway smooth muscle.