Switching inhalers in patients with asthma and COPD

For patients with asthma or chronic obstructive pulmonary disease (COPD) using an inhaler, changing inhaler regimens with or without consent can lead to unpredictable and inconsistent patient outcomes, according to results from the systematic review presented at the American Thoracic Society (ATS) International Conference 2022 held in San Francisco, California, May 13-18, 2022.

The decision to switch inhaler regimens may be driven by clinical factors such as ineffectiveness or poor response, or by non-clinical reasons such as finances or user preference. The consequences of clinical change are easily observable; however, the consequences of non-clinical change are not well documented.

The researchers sought to examine the real-world evidence on the impact of switching inhalers for non-clinical reasons in patients with asthma and COPD through a retrospective systematic review. The review analyzed 21 studies from Embase, MEDLINE, EBM Reviews and EconLit, as well as 11 conference presentations published up to mid-November 2020 reporting on inhaler switching for patients with asthma or COPD for any reason not known. did not include clinical need. Primary outcomes were categorized as follows: clinical, including symptom control, exacerbations, lung function, patient-healthcare provider relationship, satisfaction/preference, return to previous inhaler, compliance, incidence of hospitalizations, modification of rescue or rescue medication use; and cost/resource use, including direct costs, indirect costs, health care resource use, concurrent medication use, lost productivity, cost drivers. Investigators also looked at predictors of successful change.

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Matched comparative studies were prioritized. In 5 of them (N=7530), although symptom control improved, the results were ambiguous as to whether the patients accepted the change. In another matched comparison study (N=1648) that was unambiguous—that is, patients did not consent to the switch—researchers found “significantly worse disease control” after the switch. In 4 matched studies of SABA rescue medication (N = 7050), with ambiguous consent, mean daily SABA use fell after switching. In 2 other matched studies (N = 2574), where there was ambiguity about consent or clearly no consent, there was a significant or numerical increase in SABA use after the switch.

According to how the statistics were reported, in 1 matched study (N = 926), exacerbations increased significantly after the switch; in 1 matched study (N=1958) exacerbations increased numerically; in 4 matched studies (N=6534), there was no difference in exacerbations; in 1 matched study (N=2568), exacerbations numerically decreased; and in 3 matched studies (N = 8806), exacerbations significantly decreased after the switch. These researchers were not satisfied with the quality of the studies they reviewed.

The researchers urge clinicians to avoid switching inhalers without discussion with the patient. “Changing the inhaler can have very variable clinical consequences. Limited high-quality evidence suggests that switching inhalers without involving the patient in the process should be avoided,” they concluded. Investigators also cited the need for further research to investigate and determine the circumstances in which the change may be warranted.

Limitations of the study included possible selection bias and no discussion of why clinicians would switch inhalers for non-clinical reasons without discussion with the patient.

Disclosure: Some study authors have disclosed affiliations with biotechnology, pharmaceutical and/or device companies. Please see the original reference for more information.


Usmani OS, Bosnic-Anticevich SZ, Dekhuijzen P, et al. Real-world impact of non-clinical inhaler switching on patients with asthma or COPD – a systematic review. Presented at: 2022 American Thoracic Society (ATS) International Conference; May 13-18, 2022; San Francisco, CALIFORNIA. Summary P718.