Relevance of Dosage in Adherence to Treatment with Long-acting Anticholinergics in Patients with COPD

Introduction: The aim of this study was to assess the degree of adherence for two standard regimens for administrating anticholinergic drugs (12 and 24 hours) in patients with chronic obstruction of the airflow and to establish whether the use of a once-daily dose improves the level of treatment adherence.

Methods: We used long-acting anticholinergics (LAMAs) as a study variable, and included the entire health area of Castile-La Mancha, numbering 2,100,998 inhabitants, as the study population. We analyzed a total of 16,446 patients who had been prescribed a LAMA between January 1, 2013 and December 31, 2013. The follow-up period, based on a centralized system of electronic prescription management, was extended until December 2014.

Results: During 2013, the medication collected was 7.4%-10.7% higher than indicated by labeling. This was very similar for all LAMAs, irrespective of the patient's sex, the molecule, the device, and the drug dosage. We did not observe seasonal variations in the consumption of LAMAs, nor did we detect differences between prescription drugs for once-daily (every 24 hours) versus twice-daily (every 12 hours) administration, between the different molecules, or between different types of inhalers for the same molecule. The results were similar in 2014.

Conclusion: The principal conclusion of this study is that, in an area with a centralized management system of pharmacological prescriptions, adherence to treatment with LAMAs is very high, irrespective of the molecules or inhalation device. We did not find that patients who used twice-daily medication had a lower adherence.