Impact of taste changes caused by inhalers on adherence to inhalation therapy among patients with asthma and chronic obstructive pulmonary disease

Background

Adherence to inhalation therapy impacts treatment outcomes of asthma and chronic obstructive pulmonary disease. Although taste changes induced by inhaled medications may influence adherence, this matter remains underexplored. This study aimed to elucidate the characteristics of taste changes caused by inhaled medications and their association with adherence.

Methods

Consecutive patients who regularly visited our hospital from August 2023 to December 2023 were recruited. Sweet, bitter, sour, and salty taste changes were assessed using a visual analog scale. Adherence was measured using a structured questionnaire.

Results

Data from 491 inhaler responses (463 patients, aged 68.2 ± 13.5 years) were analyzed. Inhaled corticosteroid (ICS)/long-acting beta2-agonist (LABA)/long-acting muscarinic antagonist (LAMA) therapy promoted the most significant bitter taste change. Besides a long duration of taste changes (over a minute), dry powder inhaler devices (β = 0.19, P < 0.001) were significantly associated with sweet taste changes. Younger age (β = −0.17, P < 0.001), absence of a water rinse before inhalation (β = −0.09, P = 0.027), and inhalers containing LAMA (β = 0.22, P < 0.001) were associated with bitter taste changes. Older age (β = 0.10, P = 0.025) was associated with sour taste changes. Bitter taste changes (β = −0.17, P = 0.027) among users of inhalers containing LAMA and younger age (β = 0.15, P = 0.011) among users of inhalers not-containing LAMA were associated with poor adherence.

Conclusions

ICS/LABA/LAMA therapy induced the most significant bitter taste changes. The absence of a water rinse before inhalation was associated with bitter taste changes. Bitter taste changes among users of inhalers containing LAMA were correlated with poor adherence, highlighting the need for targeted interventions to improve adherence.