Outpatient Antibiotic Consumption for Urinary Infections in Croatia 2005 - 2014: What can be Learned from Utilization Trends.

Aim: The aim of this study was to determine quantities of antibiotics used mainly or exclusively for urinary tract infections in Croatia between 2005 and 2014, to describe utilisation trends, and general consequences of antibiotic consumption on antimicrobial resistance.

Methods: Antibiotic utilisation data were obtained from annual reports of both the Croatian Drug Agency and Croatian Academy of Medical Sciences. Antibiotic consumption was expressed in DDD/1000 inhabitants/day (DDD TID). Antimicrobial resistance was analysed for E. coli, E. faecalis, E. faecium, P. aeruginosa, Klebsiella spp., P. mirabilis. Descriptive statistics were used to process data and calculate trends.

Results: Overall, utilisation of antibacterials decreased by 4.8% (from 3,35 to 3,19 DDD TID), while trends of individual agents varied substantially - from 87% decline for ceftibuten to 160% rise for levofloxacin. The consumption of quinolones increased by 32.3%. This was mostly due to increased ciprofloxacin consumption (144% raise). Sulfamethoxazole-trimethoprim declined by 57%, while nitrofurantoin increased by 86%. The use of fosfomycin was marginal. Antimicrobial resistance of E. coli increased against quinolones by 54.5%, and against nitrofurantoin by 2-3%. Quinolone resistance of other pathogens (Klebiella spp, Proteus mirabilis), increased variably - between 17.2% (Klebsiella) and 90% (Proteus), while for P. aeruginosa remained the same at 22%.

Conclusion: High rates of antimicrobial utilisation require prescribing restrictions and educational interventions. The increased use of fluoroquinolones is a potentially serious public health threat due to the rapid development of resistance among uropathogens. This threat can be avoided by greater use of nitrofurantoin and fosfomycin.