Efficacy of Tiotropium as Add-on Therapy for Adults with Uncontrolled Asthma

Ralph Elvi M. Villalobos, Charles Vincent O. Uy, Marc Gregory Y. Yu and Manuel C. Jorge

Department of Medicine, College of Medicine and
Philippine General Hospital, University of the Philippines Manila

Objective. The study aimed to evaluated efficacy of tiotropium as add-on therapy on top of standard regimens for uncontrolled asthma, specifically in terms of FEV1, morning and evening PEF, reduction in exacerbations, rescue medication use, and quality of life improvement.

Methods. A search was done for eligible trials after which validity screen and data extraction was performed. Results were presented as mean differences, standard errors, and 95% confidence intervals, and graphically as forest plots. Estimates were pooled using the random effects model, with l2 and Chi2 tests used to assess heterogeneity. Adverse events were reported as dichotomous variables.

Results. Four studies were included totaling 1617 participants. The tiotropium group had statistically significant improvement in FEV1 (95% CI, 0.14 [0.09, 0.19], p<0.00001), morning (95% CI, 20.03 [11.71, 28.35], p<0.00001), and evening PEF (95% CI, 23.13 [15.18, 31.09], p<0.00001) with trend towards benefit in reduction of rescue medications (95% CI, 0.12 [-0.05, 0.25], p=0.20.) Homogeneity (i2=0%, Chi2=0.47-3.22) was found across studies.

Conclusion. Tiotropium is associated with significant improvement in pulmonary function among patients with uncrontrolled asthma, with possible benefit in reduction of rescue medications of quality of life improvement.

Key Words: asthma, tiotropium, bronchodilator agents, clinical respiratory medicine, meta-analysis