Tiotropium in chronic obstructive pulmonary disease – a review of clinical development

BACKGROUND: Bronchodilators are the mainstay of pharmacological treatment in chronic obstructive pulmonary disease (COPD), and long-acting muscarinic antagonist (LAMA) monotherapy is recommended as initial treatment for Global Initiative for Chronic Obstructive Lung Disease (GOLD) groups B, C, and D. MAIN BODY: Tiotropium bromide was the first LAMA available for COPD in clinical practice and, because of its long duration of action, is administered once daily. Tiotropium was initially available as an inhalation powder delivered via a dry-powder inhaler (DPI). Later, tiotropium also became available as an inhalation spray delivered via a soft mist inhaler (SMI). The SMI was designed to overcome or minimize some of the issues associated with other inhaler types (eg, the need for strong inspiratory airflow with DPIs). Results of short- and long-term randomized, controlled clinical trials of tiotropium in patients with COPD indicated tiotropium was safe and significantly improved lung function, health-related quality of life, and exercise endurance, and reduced dyspnea, lung hyperinflation, exacerbations, and use of rescue medication compared with placebo or active comparators. These positive efficacy findings triggered the evaluation of tiotropium in fixed-dose combination with olodaterol (a long-acting β(2)-agonist). In this review, we provide an overview of studies of tiotropium for the treatment of COPD, with a focus on pivotal studies. CONCLUSION: Tiotropium is safe and efficacious as a long-term, once-daily LAMA for the maintenance treatment of COPD and for reducing COPD exacerbations. The SMI generates a low-velocity, long-duration aerosol spray with a high fine-particle fraction, which results in marked lung drug deposition. In addition, high inspiratory flow rates are not required.