Are we still using too many antibiotics for acute bronchitis?

Abstract number: P1269

Marra F., Chong M., Patrick D.

Background: Acute bronchitis is a lower respiratory tract infection that causes reversible bronchial inflammation. In up to 95 percent of cases, the cause is viral. While antibiotics are often prescribed for patients with acute bronchitis, little evidence shows that these agents provide significant symptomatic relief or shorten the course of the illness and may in fact lead to the emergence of resistant organisms. We undertook a study to evaluate the consumption of antibiotics for acute bronchitis in British Columbia (BC), Canada.

Methods: We obtained data from the BC PharmaNet database on all outpatient oral antibiotic prescriptions from 1996 to 2005. Prescriptions were expressed as their defined daily dose (DDD) per 1,000 inhabitants according to the 2006 World Health Organisation Anatomical Therapeutic Chemical system. This data was linked to the physician billing system to determine the reason for the antibiotic prescription. Overall and class-specific rates of consumption were described by year for treatment of acute bronchitis.

Results: In 1996, the BC consumption rate for all antibiotics used for acute bronchitis was 0.98 DDD per 1000 inhabitant-days. This decreased to a low of 0.63 DDD per 1000 inhabitant-days in 2002 but since then has increased such that in 2005, the rate was 0.81 DDD per 1000 inhabitant-days. Increases in fluoroquinolone use, specifically moxifloxacin (37-fold from year 2000 to year 2005), clarithromycin (3-fold) and azithromycin (7-fold) were seen while use of tetracyclines and B lactams declined by approximately 50%.

Conclusions: Physicians continue to prescribe antibiotics for acute bronchitis and we need to implement a multi-pronged approach within the province to change prescribing.