PURPOSE: Budesonide/formoterol dry-powder inhaler (DPI) and fluticasone/salmeterol DPI may differ in their impact on asthma outcomes due to different drug properties and dosing regimens. We evaluated the effects of these combination therapies on measures of asthma control.
METHODS: The United Kingdom's General Practice Research Database was used to identify asthma patients with a first prescription for budesonide/formoterol or fluticasone/salmeterol after May 2001. We used Poisson regression and Cox proportional hazards models to compare budesonide/formoterol and fluticasone/salmeterol users with either an intent-to-treat approach or during persistent-treatment, on the frequency of prescriptions or healthcare events in the year after first prescription, adjusting for covariates measured during the year before this first prescription.
RESULTS: There were 6,918 first-time users of budesonide/formoterol and 16,157 of fluticasone/salmeterol. In the intent-to-treat analysis; budesonide/formoterol subjects received 14% fewer prescriptions for their combination therapy than fluticasone/salmeterol subjects (95% CI: 12%-16%), 8% fewer prescriptions for other asthma medications (95% CI: 6%-10%), 9% fewer antibiotic prescriptions (95% CI: 6%-12%). Rates of asthma hospitalization and physician visits were similar for the two groups. After adjusting for the lower prior rate of specialist referrals for budesonide/formoterol, there were 17% (95% CI: 8%-27%) more referrals in the following year. The mean duration of persistent treatment was 3 months, but 13% longer for budesonide/formoterol (95% CI:11%-16%). During persistent treatment, budesonide/formoterol subjects received 11% less prescriptions for their combination therapy (95% CI: 9%-13%) and 8% less total prescriptions for asthma medications (95% CI: 6%-10%), while the rate of asthma hospitalization was reduced by 16% (95% CI: 9%-23%) and the number of antibiotic prescriptions was reduced by 11% (95% CI: 7%-15%).
CONCLUSION: This observational cohort study suggests that equivalent or better asthma control may be achieved with less budesonide/formoterol than fluticasone/salmeterol in the first year of use. These findings need to be confirmed using a randomized trial approach.
CLINICAL IMPLICATIONS: Flexible dosing with combination therapy maybe as effective as standard dosing and at lower doses of medication.
DISCLOSURE: Samy Suissa, No Product/Research Disclosure Information; Grant monies (from industry related sources) Samy Suissa received funding for research grants from AstraZeneca and Glaxo-Smith-Kline. Pierre Ernst received an investigator initiated research grant of $100,000 from Glaxo Smith Kline in 2003-5. He has also recently been awarded $150,000 from Glaxo Smith Kline as co-investigator of an investigator initiated research grant for 2007-8; Consultant fee, speaker bureau, advisory committee, etc. Samy Suissa has been reimbursed for attending Advisory Board meetings, conferences and participating as a speaker. In scientific meetings financed by various pharmaceutical companies (AstraZeneca, Boehringer Ingelheim, Glaxo-Smith-Kline, Pfizer and Sepracor). Pierre Ernst has received speaker fees and serves on advisory boards for Altana, Astra Zeneca, Glaxo Smith Kline, Merck Frosst, Novartis.