Background: The role of the recently described glycopyrronium reversibility in obstructive airway diseases (OADs) needs to be elaborated.

Objective: To assess glycopyrronium reversibility in OADs

Methods: Clinically suspected OAD patients (presence of any three of these symptoms: cough, wheeze, SOB, expectoration, and chest-tightness) were selected on consent. Asthma was identified with FEV1 reversibility ?200ml and>12% and COPD was identified with FEV1 reversibility <200ml and/or <12% and FEV1/FVC<0.7. The redundant group was marked ?indeterminate?. Selected subjects underwent spirometry for serial reversibility test with salbutamol followed by glycopyrronium as per protocol. The results of group specific changes were analysed statistically.

Results: Out of 420 patients recruited from outpatient services, asthma, COPD, and indeterminate groups consisted of 127, 160, and 133 subjects respectively. Their salbutamol reversibility was 351.4±129.8ml (26.63±14.23%), 43.38±57.97ml (3.844±4.698%), 128.3±75.05ml (11.58±7.773%) and the add-on glycopyrronium reversibility was 82.52±136.2 ml, 96.81±101.8ml and 69.85±104.0 ml respectively. In terms of combined reversibility, the changes noted were 433.1±202.0, 139.9±114.0 and 199.1±129.0 ml for asthma, COPD and indeterminate respectively. The combined changes were found statistically significant over salbutamol alone for asthma (p=0.0002), COPD (p<0.0001) and indeterminate (p<0.0001).

Conclusions: Glycopyrronium offers significant but variable add-on reversibility to all types of OAD (asthma, COPD and indeterminate) best reversibility to COPD. Its clinical significance of glycopyrronium reversibility in OAD demands further research.