Tiotropium induced bronchodilation and protection from dynamic hyperinflation is independent of extent of emphysema in COPD

Efficacy of Nebulized Glycopyrrolate on Lung Hyperinflation in Patients with COPD

INTRODUCTION

Lung hyperinflation in chronic obstructive pulmonary disease (COPD) is associated with activity limitation, impaired cardiac output, and mortality. Several studies have demonstrated that long-acting muscarinic antagonists (LAMAs) delivered by dry powder inhalers can promote lung deflation; however, the potential of nebulized LAMAs on improving hyperinflation in COPD is currently unknown.

METHODS

This single-center, randomized, double-blind, two-way crossover study (NCT04155047) evaluated the efficacy of a single dose of nebulized LAMA [glycopyrrolate (GLY) 25 µg] versus placebo in patients with COPD and lung hyperinflation. Patients with moderate-to-severe COPD and a residual volume (RV) ≥ 130% of predicted normal were included. The primary endpoint was changed from baseline in RV at 6 h post-treatment. Other endpoints included changes from baseline in spirometric and plethysmographic measures up to 6 h post-treatment.

RESULTS

A total of 22 patients (mean pre-bronchodilator RV, 153.7% of predicted normal) were included. The primary objective of the study was not met; the placebo-adjusted least squares (LS) mean [95% confidence interval (CI) change from baseline in RV with GLY at 6 h post-treatment was - 0.323 l (- 0.711 to 0.066); p = 0.0987]. A post hoc evaluation of the primary analysis was conducted after excluding a single statistical outlier; substantial improvements in RV with GLY compared with placebo was observed after exclusion of this outlier [placebo-adjusted LS mean change from baseline (95% CI) in RV was - 0.446 l (- 0.741 to - 0.150)]. Improvements from baseline were also observed with GLY compared with placebo in spirometric and plethysmographic measures up to 6 h post-treatment. GLY was generally safe, and no new safety signals were detected.

CONCLUSIONS

This is the first study to evaluate the effect of nebulized GLY on lung deflation. Nebulized GLY resulted in marked improvements in RV up to 6 h post-treatment, compared with placebo. Improvements were also observed with GLY in spirometric and plethysmographic parameters of lung function.

TRIAL REGISTRATION

ClinicalTrials.gov identifier, NCT04155047.

Comparing dynamic hyperinflation and associated dyspnea induced by metronome-paced tachypnea versus incremental exercise

Dynamic hyperinflation (DH) during exercise is associated with both dyspnea and exercise limitation in COPD. Metronome-paced tachypnoea (MPT) is a simple alternative for studying DH. We compared MPT with exercise testing (XT) as methods of provoking DH, and assessed their relationship with dyspnea. We studied 24 patients with moderate COPD (FEV1 59 ± 9% predicted) after inhalation of ipratropium/salbutamol combination or placebo in a double-blind, crossover design. Inspiratory capacity (IC) was measured at baseline and after 30 seconds of MPT with breathing frequencies (fR) of 20, 30 and 40 breaths/min and metronome-defined I:E ratios of 1:1 and 1:2, in random sequence, followed by incremental cycle ergometry with interval determinations of IC. DH was defined as a decline in IC from baseline (∆IC) for both methods. Dyspnea was assessed using a Borg CR-10 scale. ∆IC during MPT was greater with higher fR and I:E ratio of 1:1 versus 1:2, and less when patients were treated with bronchodilator rather than placebo (P = 0.032). DH occurred during 19 (40%) XTs, and during 35 (73%) tests using MPT. Eleven of 18 (61%) non-congruent XTs (where DH occurred on MPT but not XT) terminated before fR of 40 breaths/min was reached. Although greater during XT, the intensity of dyspnea bore no relationship to DH during either MPT and XT. MPT at 40 breaths/min and I:E of 1:1 elicits the greatest ∆IC, and is a more sensitive method for demonstrating DH. The relationship between DH and dyspnea is complex and not determined by DH alone.

Determinants of dynamic hyperinflation during metronome-paced tachypnea in COPD and normal subjects

In COPD, dynamic hyperinflation (DH) occurs during exercise and during metronome-paced tachypnea (MPT). We investigated the relationship of DH with breathing pattern and ventilation (V˙E) in COPD and normal subjects (NS). In 35 subjects with moderate COPD and 17 younger healthy volunteers we measured inspiratory capacity (IC), breathing frequency (fR), expiratory time (TE), ventilation (V˙E) and end-tidal carbon dioxide tension (PETCO2) at baseline and after 30s of MPT at 40breaths/min with metronome-defined I:E ratios of 1:1 and 1:2. A reduction in IC (ΔIC) was taken to indicate DH. In COPD subjects, DH correlated with TE but not with V˙E or PETCO2, and was best predicted by total lung capacity. NS also showed DH (although less than in COPD), which correlated with PETCO2 but not with fR, TE or V˙E. We conclude that MPT evokes DH in both NS and patients with COPD. TE is the most important determinant of DH during MPT in patients with COPD.

Tiotropium: what came after the UPLIFT study

INTRODUCTION

Chronic obstructive pulmonary disease (COPD) is characterized by a progressive bronchial obstruction, and bronchodilators represent the maintenance therapeutic choice. Tiotropium is an anticholinergic drug that is proved to be safe, efficient and simple to handle; Respimat® technology was recently introduced as a new device for tiotropium administration.

AREAS COVERED

This paper reviews clinical trials and meta-analyses, with tiotropium efficacy as a primary end point, found in MedLine, the Cochrane trials database and Embase. Only the literature published after the UPLIFT study has been considered.

EXPERT OPINION

Data published after the UPLIFT study confirms the efficacy of tiotropium as maintenance COPD therapy and its capacity to reduce airflow obstruction, as well as lung hyperinflation. Nevertheless, there is a certain inhomogeneity in the definition and evaluation of COPD exacerbations, in lung functional parameters and quality-of-life assessment, and there has not always been a proper comparison between tiotropium and other long-acting bronchodilators. Respimat is comparable in efficacy to the HandiHaler®, using bioequivalent doses of tiotropium.

Comparison of efficacy of long-acting bronchodilators in emphysema dominant and emphysema nondominant chronic obstructive pulmonary disease

BACKGROUND

The purpose of this study was to clarify the association between morphological phenotypes according to the predominance of emphysema and efficacy of long-acting muscarinic antagonist and β(2) agonist bronchodilators in patients with chronic obstructive pulmonary disease (COPD).

METHODS

Seventy-two patients with stable COPD treated with tiotropium (n = 41) or salmeterol (n = 31) were evaluated for pulmonary function, dynamic hyperinflation following metronome-paced incremental hyperventilation, six-minute walking distance, and St George's Respiratory Questionnaire (SGRQ) before and 2-3 months following treatment with tiotropium or salmeterol. They were then visually divided into an emphysema dominant phenotype (n = 25 in the tiotropium-treated group and n = 22 in the salmeterol-treated group) and an emphysema nondominant phenotype on high-resolution computed tomography, and the efficacy of the two drugs in each phenotype was retrospectively analyzed.

RESULTS

Tiotropium significantly improved airflow limitation, oxygenation, and respiratory impedance in both the emphysema dominant and emphysema nondominant phenotypes, and improved dynamic hyperinflation, exercise capacity, and SGRQ in the emphysema dominant phenotype but not in the emphysema nondominant phenotype. Salmeterol significantly improved total score for SGRQ in the emphysema phenotype, but no significant effects on other parameters were found for either of the phenotypes.

CONCLUSION

These findings suggest that tiotropium is more effective than salmeterol for airflow limitation regardless of emphysema dominance, and also can improve dynamic hyperinflation in the emphysema dominant phenotype, which results in further improvement of exercise capacity and health-related quality of life.

Tiotropium bromide: an update

Tiotropium bromide is a once-daily inhaled anticholinergic bronchodilator. It works by blocking the muscarinic receptors in airway smooth muscle. Tiotropium has a wide therapeutic margin, due to its poor gastrointestinal absorption and its very low systemic bioavailability. The drug is mainly indicated in COPD patients. Clinically relevant outcomes such as significant improvements in spirometry, hyperinflation, dyspnea, heath status, acute exacerbations and mortality have been consistently observed in tiotropium clinical trials, and the drug has been shown to reduce the risk of mortality due to cardiac-vascular disease and respiratory failure. The main side effect reported is dryness of the mouth. Some subgroups of asthmatics also seem to respond to anticholinergic drugs: among them, those with the Arg/Arg genotype for the beta2-adrenergic receptor and those with a high percentage of neutrophils in sputum.