Ten years of antibiotic consumption in ambulatory care: trends in prescribing practice and antibiotic resistance in Austria

Abstract number: P754

Metz-Gercek S., Maieron A., Straub R., Wieninger P., Apfalter P., Mittermayer H.

Objectives: The primary aims of this study were to determine (i) the quantity and pattern of antibiotic use in Austria between 1998 and 2007, (ii) to analyze antibiotic resistance rates in relation to antibiotic consumption in important clinical situations in order to provide data for empiric therapeutic regimens in key indications.

Methods: Consumption data and resistance data were obtained via the Austrian European Antimicrobial Resistance Surveillance System (EARSS) and the European Surveillance on Antimicrobial Consumption (ESAC). The Anatomical therapeutical chemical (ATC) classification and the defined daily dose (DDD) measurement units were assigned to the data. DDDs and the number of packages (PID) were used to calculate the amount of antibiotic consumption. Antibiotic resistance was expressed in resistance rates being the percentage of resistant isolates compared to all isolates of one bacterial species.

Results: The overall antibiotic consumption measured in DIDs showed an increase of 10% between 1998 and 2007 whereas in PIDs a decrease of 3% was found. The consumption for substances within the drug utilisation 90% segment measured in PID increased for ciprofloxacin (+118.9), clindamycin (+76.3), amoxicillin/clavulanic acid (+61.9%), cefpodoxim (+31.6), azithromycin (+24.7) and decreased for erythromycin (-79.5%), trimethoprim (-56.1%), norfloxacin (-48.8%), doxycycline (-44.6), cefaclor (-35.1%), penicillin [(-34.0%), (pen)] amoxicillin (-22.5), minocycline (-21.9%) and clarithromycin (-9.9%). Since 2001, an increase in the percentage of resistant invasive E. coli isolates for aminopenicillins (from 35%-53%), fluoroquinolones (from 7%-25.5%) and 3rd generation cephalosporins (from 0%-8.8%) was observed. The percentage of pneumococcal isolates (spn) non- or intermediate susceptible to pen remained stable over the years at around 5%. In macrolides the rate of resistant isolates increased from 5% to 12.8% with a peak in 2005 at 14.7%.

Conclusions: The Austrian resistance data do not explain the change in prescribing practice. The increased use of ciprofloxacin has most likely contributed to rising resistance rates in E. coli. Because of very low levels of resistance against penicillin in spn there is no need for the application of broadspectrum pen, pen combination products (amoxicillin/clavulanic acid), third generation cephalosporins as well as new fluoroquinolones for the treatment of community acquired pneumonia in ambulatory care patients.

Session Details

Date: 16/05/2009
Time: 00:00-00:00
Session name: 19th European Congress of Clinical Microbiology and Infectious Diseases
Location: Helsinki, Finland, 16 - 19 May 2009
Presentation type:
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