UMECLIDINIUM IS A LONG-ACTING, ANTIMUSCARINIC AGENT, 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. THE BRONCHODILATION FOLLOWING INHALATION OF UMECLIDINIUM IS PREDOMINANTLY A SITE-SPECIFIC EFFECT.