Abstract / Summary
Abstract Background Patients undergoing biologic therapy need to continue using an inhaler to deliver aerosol drugs via the respiratory tract. In a significant fraction of the patients the improvement of the symptoms and reduction of the inflammation is complemented also by the improvement of the lung function. The aim of this study was to conduct measurements of the inhalation parameters of the patients under biologic therapy through four selected dry powder inhalers to evaluate whether the amelioration of their disease is reflected also in their inhalation performance while using their inhalers. Another aim was to correlate the inhalation parameters through the inhalers with patients’ baseline spirometric data. Methods 50 severe asthmatic patients who were under biologic therapy at the time of the recruitment were included in a single-center cross-sectional clinical study. Normal spirometry and measurement of inhalation curves while inhaling through Breezhaler ® , Turbuhaler ® , NEXThaler ® and Ellipta ® was performed. Results The mean vales of the peak inspiratory flow through the device (PIF dev ) were 103.2 L/min, 75.1 L/min, 88.9 L/min and 109.8 L/min for Breezhaler ® , Turbuhaler ® , NEXThaler ® and Ellipta ® . All the patients were able to inhale by at least 30 L/min through each device. The mean inspiratory volume (IV) inhaled through the same devices was 2.6 L, 2.3 L, 2.1 L and 2.6 L, respectively. Our results also showed that the main predictors of lung deposition of aerosol drugs (PIF dev and IV dev ) correlated well with the corresponding baseline spirometric parameters (PIF and IVC), but also the score of the asthma control test (ACT) in the case of the peak flow. 61-74% of the variance of PIF dev could be explained by the variance of its predictors. The same percentages were 58-87% in the case of IV dev . Conclusions The main outcome of this analysis was that in terms of PIF dev and IV dev , asthmatic patients under biological therapy performed as good as healthy subjects and significantly better than COPD patients who were involved in our similar studies in the past. Furthermore, due to the strong correlations shown, it is possible to associate the baseline spirometric parameters with the corresponding parameters through inhaler devices, but predicting power of spirometric parameters is restricted to population level. Trial registration The study protocol (BEP-2110/01, 2021 V2) was approved by the National Institute of Pharmacy and Nutrition (OGYÉI/74-3/2022), after the positive evaluation statement of the Ethical Committee of the National Medical Research Council (ETT TUKEB, IV/657- 3 /2022/EKU) registered on 12/02/2022. The registration took place before the first participant was enrolled.