Given the high proportion of patients with asthma who remain uncontrolled despite controller treatment, there remains a need for the development of more effective treatment options with a proven safety and tolerability profile. Recently, asthma guidelines have evolved to incorporate new therapies, including long-acting muscarinic antagonists (LAMAs) and biologics. Here we focus on the safety profile of tiotropium, a LAMA, using data from the large-scale UniTinA-asthma® clinical trial program, which investigated the use of tiotropium in over 6000 patients with asthma who remained symptomatic despite receiving inhaled corticosteroids (ICS) maintenance therapy, with or without other adjunct therapies. The large number of patients included allows robust analysis of safety and tolerability. Overall, a similar incidence of patients reporting any adverse event (AE) was observed in the tiotropium (5 µg and 2.5 µg) and placebo groups. Asthma worsening, decreased peak expiratory flow, and upper respiratory tract infections were the most frequently reported AEs. Serious AEs (SAEs) and investigator-defined drug-related AEs were infrequently reported across all treatment groups, including the placebo group, and there were no deaths in any study. Reports of side effects typically associated with anticholinergic drugs, such as dry mouth and urinary retention, were either infrequent or not reported in children, adolescents or adults. The similar proportions of tiotropium- versus placebo-treated patients reporting AEs and SAEs in African-American and Japanese populations, as well as in elderly patients, contribute to the accumulating evidence of the safety and tolerability of tiotropium across broad ethnic and age populations.
Keywords: anticholinergics; asthma; long-acting muscarinic antagonists; safety; tiotropium.