Delivery characteristics and patients' handling of two single-dose dry-powder inhalers used in COPD.

For optimal efficacy, an inhaler should deliver doses consistently and be easy for patients to use with minimal instruction. The delivery characteristics, patients' correct use, and preference of two single-dose dry powder inhalers (Breezhaler and HandiHaler) were evaluated in two complementary studies. The first study examined aerodynamic particle size distribution, using inhalation profiles of seven patients with moderate to very severe chronic obstructive pulmonary disease (COPD). The second was an open-label, two-period, 7-day crossover study, evaluating use of the inhalers with placebo capsules by 82 patients with mild to severe COPD. Patients' correct use of the inhalers was assessed after reading written instructions on Day 1, and after training and 7 days of daily use. Patients' preference was assessed after completion of both study periods. Patient inhalation profiles showed average peak inspiratory flows of 72 L/minute through Breezhaler and 36 L/minute through HandiHaler. For Breezhaler and HandiHaler, fine particle fractions were 27% and 10%, respectively. In the second study, correct use of Breezhaler and HandiHaler was achieved by > 77% of patients for any step after 7 days; 61% of patients showed an overall preference for Breezhaler and 31% for HandiHaler (P = 0.01).Breezhaler is a low-resistance inhaler suitable for use by patients with a range of disease severities. Most patients used both inhalers correctly after 7 days, but more patients showed an overall preference for the Breezhaler compared with the HandiHaler. These are important factors for optimum dose delivery and successful COPD management.