Differences in Adherence to Common Inhaled Medications in COPD

Objective: To study differences in adherence to common inhaled medications in COPD.

Methods: Adherence of 795 patients was recorded from pharmacy records over 3 years in the COMIC cohort. It was expressed as percentage and deemed good at ≥75-≤125%, sub-optimal ≥50-<75%, and poor <50% (underuse) or >125% (overuse). Most patients used more than one medication, so we present 1379 medication periods.

Results: The percentages of patients with good therapy adherence ranged from 43.2 (beclomethasone) -75.8% (tiotropium); suboptimal from 2.3 (budesonide) -23.3% (fluticasone); underuse from 4.4 (formoterol/budesonide) -18.2% (beclomethasone); and overuse from 5.1 (salmeterol) -38.6% (budesonide). Patients using fluticasone or salmeterol/fluticasone have a 2.3 and 2.0-fold increased risk of suboptimal versus good adherence compared to tiotropium. Patients using salmeterol/fluticasone or beclomethasone have a 2.3- and 4.6-fold increased risk of underuse versus good adherence compared to tiotropium. Patients using budesonide, salmeterol/fluticasone, formoterol/budesonide, ciclesonide and beclomethasone have an increased risk of overuse versus good adherence compared to tiotropium. Adherence to inhalation medication is inversely related to lung function.

Conclusion: Therapy adherence to inhalation medication for the treatment of COPD is in our study related to the medication prescribed. Tiotropium showed the highest percentage of patients with good adherence, followed by ciclesonide, both dosed once daily. The idea of improving adherence by using combined preparations cannot be confirmed in this study. Further research is needed to investigate the possibilities of improving adherence by changing inhalation medication.