The aim of this study was to analyze the possibility of inhaled drug substitutions. Methods. The authors analyzed spontaneous reports from the Federal database of adverse events associated with switching a patient from the reference ipratropium bromide/fenoterol combination to a generic one. Results. The drug substitution within one INN was reported in 15% of all reports about adverse events related to prescription of this INN. A great deal of these reports was related to drug substitution in elderly. Generally, the reference drug was well tolerated, but its substitution to a generic drug resulted in lower efficacy (18.8%) or development of adverse events, mostly respiratory (51.8% of all adverse events). Conclusion. The inhaled drug substitution could be associated with a potential risk of adverse events or lower efficacy. The substitution of inhaled drugs within one INN should be made with caution. © 2018 National Research University Higher School of Economics. All rights reserved.