Tiotropium - Advancing the treatment of COPD

Inhaled anticholinergic bronchodilators are a treatment of choice for chronic obstructive pulmonary disease (COPD). Tiotropium is currently the only long-acting inhaled anticholinergic bronchodilator available and works by selectively inhibiting muscarinic receptors involved in mucus hypersecretion and bronchoconstriction, two characteristic features of COPD. Clinical trials have demonstrated the efficacy of tiotropium across all degrees of severity of stable COPD. Tiotropium improves airway function, symptoms of dyspnoea, exercise endurance and health status. Treatment with tiotropium also reduces acute exacerbations associated with COPD as well as associated hospitalisations. The clinical improvements observed with tiotropium are associated with changes in airway volume, particularly inspiratory capacity, which translate into improvements in patient-centred outcomes, such as breathlessness during exercise. Emerging evidence indicates that tiotropium may exert additive effects when used in combination with the long-acting β₂-agonist (LABA), formoterol, consistent with the current recommendations for combination therapy in patients who do not respond to a single bronchodilator. Encouraging results have also been obtained with tiotropium in triple combination with salmeterol/ fluticasone propionate. Furthermore, post hoc analyses suggest that tiotropium may slow the rate of decline in lung function characteristic of COPD. Recent studies indicate that combining tiotropium therapy with pulmonary rehabilitation programmes can yield significant improvements in exercise endurance time. In safety evaluations, tiotropium was generally well tolerated with a similar safety profile to ipratropium, a short-acting anticholinergic bronchodilator. Dry mouth is the most common adverse event reported with tiotropium, although this is generally transient and does not lead to treatment discontinuation.