A 1-year comparison of turbuhaler vs pressurized metered-dose inhaler in asthmatic patients.

An open, randomized, parallel-group study was conducted to investigate whether asthmatic patients, considered adequately treated with a corticosteroid and/or short-acting beta 2-agonist via pressurized metered-dose inhaler (pMDI), could be transferred to a corresponding nominal dose of budesonide and/or terbutaline via Turbuhaler, an inspiratory flow-driven multidose dry powder inhaler (Astra Draco; Lund, Sweden), without a decrease in the effect of treatment. One thousand four patients (555 women; mean age, 44 years; mean peak expiratory flow [PEF], 102% predicted normal value) were randomized and treated with either pMDI (current therapy) or Turbuhaler for 52 weeks. The variables studied were asthma-related events, morning PEF, and inhaler-induced clinical symptoms. Asthma-related events were defined in two ways: (1) sum of health-care contacts plus doublings or additions of steroids, and (2) number of 2 consecutive days with PEF less than 80% of baseline. Baseline was obtained from a 2-week run-in period while receiving previous therapy. No statistically significant difference was found in asthma-related events according to definition 1. According to definition 2, there was a statistically significant difference between the groups in favor of Turbuhaler (p = 0.008). The mean number of events was 1.7 with Turbuhaler and 2.2 with pMDI. The mean number of weeks per patient with a PEF less than 90% of baseline was 4.5 with Turbuhaler compared with 6.0 with pMDI (p = 0.002). The sum of inhaler-induced symptoms after 1 year of use was statistically significantly lower with Turbuhaler (0.40) than with pMDI (0.75) (p = 0.0001). In conclusion, budesonide and terbutaline in Turbuhaler offered a superior alternative to corticosteroids and bronchodilators delivered by pMDIs in the maintenance treatment of asthma.