RECENT TRENDS IN THE USE OF INHALED BETA(2)-ADRENERGIC AGONISTS AND INHALED CORTICOSTEROIDS IN SASKATCHEWAN

Objective: To examine recent trends in the use of inhaled beta(2)-adre nergic agonists and inhaled corticosteroids for the treatment of asthm a among Saskatchewan residents and to determine whether these trends a re in keeping with widely publicized guidelines recommending a reducti on in the use of agents to treat symptoms (i.e., inhaled beta(2)-adren ergic agonists) and increased use of prophylactic agents (i.e., inhale d corticosteroids). Design: Descriptive pharmacoepidemiologic study co nducted with the use of data from the computerized database of the Sas katchewan Prescription Drug Plan. Setting: Saskatchewan. Patients: Sas katchewan residents 5 to 54 years of age who received one or more outp atient prescriptions for drugs to treat asthma (inhaled drugs, ingeste d beta(2)-adrenergic agonists and ingested methylxanthines) from 1989 to 1993. Outcome measures: Epidemiologic trends, calculated for each y ear: number of prescriptions per 1000 per sons; number of patients who received prescriptions for inhaled corticosteroids, inhaled beta(2)-a drenergic agonists and any type of drug to treat asthma; mean number o f such prescriptions per patient, and weighted mean amount of salbutam ol, fenoterol and beclomethasone dispensed per patient. Results: There has been an increase in the proportion of the population receiving pr escriptions for drugs to treat asthma. The number of patients receivin g these drugs per 1000 people rose during the study period from 33.38 to 46.59 for any drug to treat asthma, from 24.70 to 33.77 for inhaled beta(2)-adrenergic agonists and from 6.1 to 19.9 for inhaled corticos teroids. The mean number of prescriptions per patient decreased steadi ly for all drugs to treat asthma (from 5.34 in 1989 to 3.88 in 1993), for inhaled beta(2)-adrenergic agonists (from 4.35 to 3.09) and for in haled corticosteroids (from 2.98 to 2.25). The weighted mean amount of inhaled salbutamol dispensed per patient per year decreased by 40%, f rom 178.08 mg in 1989 to 109.14 mg in 1993. The weighted amount of fen oterol dispensed per patient per year declined even more, by 58%, from 387.91 mg in 1989 to 164.00 mg in 1993. Conversely, the weighted amou nt of inhaled beclomethasone dispensed per patient per year increased by 35% from 46.95 mg in 1989 to 63.50 mg in 1992, then dropped to 56.1 7 mg per year in 1993. Conclusion: These data demonstrate a substantia l change in Saskatchewan in the prescribing of drugs to treat asthma; they suggest that many physicians responded to current guidelines advo cating increased attention to prevention of airway inflammation in the treatment of asthma.