The impact of unsupervised and unconsented switch of inhalers in patients with controlled asthma – A targeted literature review

Inhaler combination formulations consisting of an inhaled corticosteroid (ICS) (fluticasone propionate) and a long-acting β2 agonist (salmeterol xinafoate) are indicated as maintenance treatments for patients with asthma and/or for selected patients with chronic obstructive pulmonary disease. The emergence of generic equivalents to branded inhalers is expected to offer economic edge/savings; however, some may argue that cost advantages offered by generic inhalers may be offset by worsening outcomes due to improper inhaler use, reduced adherence, and consequently worse disease control. To understand how unsupervised and unconsented switch of dry-powder inhalers and/or metered-dose inhalers affects clinical and humanistic outcomes in asthma, comprehensive searches of Embase and MEDLINE were conducted to identify research articles published in the English language since 2011. Patients with asthma of any age who underwent an unsupervised and unconsented switch from an ICS/long-acting β2 agonist to another (brand-to-generic or brand-to-brand) for non-medical reasons were the target of this research. Relevant outcomes included asthma control, medication adherence, and healthcare resource utilization. In total, 11 studies were identified for review (ten non-interventional and one post hoc); cohorts ranged from 19 to 42,553 patients. Six studies indicated that unsupervised and unconsented inhaler switch had a negative impact on asthma control; six studies indicated reduced medication adherence post-switching; and five studies reporting healthcare resource utilization showed it was unchanged or increased post-switching. Findings from this targeted review support concerns that unsupervised and unconsented inhaler switch has a largely negative impact on asthma-associated outcomes. Additional studies are warranted to further explore unsupervised and unconsented switch in asthma.