Metered-dose inhalers lead to better asthma control than dry-powder inhalers

Many patients with chronic obstructive pulmonary disease (COPD) and asthma do not use inhaler devices properly, which can contribute to poor disease control. Dr.Wijdan H Ramadan at Department of Pharmacy Practice, School of Pharmacy, Lebanese American University, Byblos, Lebanon, and associates conducted a prospective comparative observational study to assess the technical and safe use of dry powder inhalers (DPIs) versus pressurized metered-dose inhalers (MDIs) in adult patients with COPD or asthma in Lebanon.The study also evaluated patient satisfaction among MDI and DPI users.The researchers found that in patients with asthma, metered-dose inhalers (MDIs) are associated with better disease control and treatment adherence compared with dry-powder inhalers (DPIs), but both provide equivalent treatment satisfaction, The study has bee published in the journal Respiratory Care.

In the study, the researchers evaluated 200 patients with asthma who were randomly assigned to receive either MDI (n=115) or DPI (n=85). Airway obstruction on spirometry, a fraction of expired nitric oxide (FENO), and asthma control were evaluated between both the treatment groups. Treatment Satisfaction Questionnaire for Medication (TSQM) score was used to assess treatment satisfaction and Medication Adherence Questionnaire (MAQ) score was used to evaluate treatment adherence.

Of 200 patients, 49.0% of patients had an obstructive defect on spirometry and 19.0% of patients had a fraction of expired nitric oxide levels (FENO) >25 parts per billion (ppb). A number of MDI users had well-controlled asthma vs DPI users (40.9% vs 17.6%; P=.001). MDI users had greater treatment adherence and better TSQM scores for Effectiveness (P=.004), Convenience (P=.02), and Global Satisfaction (P=.035) vs DPI users. MDI users had significantly better MAQ scores than DPI users (P= .043). TSQM scores were significantly correlated with MAQ scores (P<.05). No significant correlation was found between any TSQM score and pulmonary function or FENO concentration.