RT Journal Article SR Electronic T1 Long term effect of doxycycline in asthma: a real world observation JF European Respiratory Journal JO Eur Respir J FD European Respiratory Society SP PA4686 DO 10.1183/1393003.congress-2017.PA4686 VO 50 IS suppl 61 A1 Parthasarath Bhattacharyya A1 Surita Sarkar A1 Soumen Das A1 Dipanjan Saha YR 2017 UL http://erj.ersjournals.com/content/50/suppl_61/PA4686.abstract AB Background: The inhibition of matrix metalloproteinase (MMPs) and IgE could be a prospective therapy of treating inflammation and remodelling of asthma. Doxycycline, a well-known antibiotic, may satisfy the goal for having both the properties.Objective: To look for effect on long term add-on oral doxycycline in patients of asthma.Methods: In a prospective, real-world observation, a cohort of asthmatic patients were treated with standard therapy with or without long term use of oral add-on doxycycline. The changes in spirometric variables in terms of post bronchodilator FEV1, FEV1/FVC, and FEF25–75 were noted.Results: A group of patients in add-on doxycycline (n=73) and COPD therapy only (n=72) groups with similar age (p<0.05) and BMI but different baseline post bronchodilator FEV<1 (1.25±0.50 and 1.66±0.73 Litres) were treated for similar length of time (346.89±269.61 and 335.82±274.51 days) respectively. The mean absolute change in post-bronchodilator FEV1 has been +130 ml (p=.0000) in add-on doxycycline group while it was -70 ml (p= 0.027) in those receiving COPD therapy alone. There were parallel changes in FEV1/FVC (p<0.005) and FEF<25-75 (p<0.00001) in the doxycycline treated patients former signifying overall improvement in lung function.Conclusion: Add-on doxycycline appears to be well tolerated and results in significant improvement in the lung function in asthmatic patients on long term use. The observation deserves further validation.