ABSTRACT: Tiotropium is prescribed for the treatment of chronic obstructive pulmonary disease (COPD) and delivered via HandiHaler(®) (18 ?g once daily) or Respimat(®) Soft Mist™ inhaler (5 ?g once daily). The recent TIOtropium Safety and Performance In Respimat(®) (TIOSPIR™) study demonstrated that both exhibit similar safety profiles. This analysis provides an updated comprehensive safety evaluation of tiotropium(®) using data from placebo-controlled HandiHaler(®) and Respimat(®) trials.Pooled analysis of adverse event (AE) data from tiotropium HandiHaler(®) 18 ?g and Respimat(®) 5 ?g randomized, double-blind, parallel-group, placebo-controlled, clinical trials in patients with COPD (treatment duration ?4 weeks). Incidence rates, rate ratios (RRs), and 95% confidence intervals (CIs) were determined for HandiHaler(®) and Respimat(®) trials, both together and separately.In the 28 HandiHaler(®) and 7 Respimat(®) trials included in this analysis, 11,626 patients were treated with placebo and 12,929 with tiotropium, totaling 14,909 (12,469 with HandiHaler(®); 2,440 with Respimat(®)) patient-years of tiotropium exposure. Mean age was 65 years, and mean prebronchodilator forced expiratory volume in 1 second (FEV1) was 1.16 L (41% predicted). The risk (RR [95% CI]) of AEs (0.90 [0.87, 0.93]) and of serious AEs (SAEs) (0.94 [0.89, 0.99]) was significantly lower in the tiotropium than in the placebo group (HandiHaler(®) and Respimat(®) pooled results), and there was a numerically lower risk of fatal AEs (FAEs) (0.90 [0.79, 1.01]). The risk of cardiac AEs (0.93 [0.85, 1.02]) was numerically lower in the tiotropium group. Incidences of typical anticholinergic AEs, but not SAEs, were higher with tiotropium. Analyzed separately by inhaler, the risks of AE and SAE in the tiotropium groups remained lower than in placebo and similarly for FAEs.This analysis indicates that tiotropium is associated with lower rates of AEs, SAEs, and similar rates of FAEs than placebo when delivered via HandiHaler(®) or Respimat(®) (overall and separately) in patients with COPD.