Treatment failures after antibiotic therapy of uncomplicated urinary tract infections - A prescription database study

Objectives - The efficacy of sulfamethizole and pivmecillinam in the treatment of urinary tract infections (LITI) has been questioned because of an increase in the prevalence of resistant strains. The aim of this study was to describe the risk of treatment failures over the last 10 years. Design - Retrospective cohort study. Material - Data were retrieved from Odense Pharmaco Epidemiological Database and consisted of women receiving sulfamethizole (n = 44 715) or pivmecillinam (n = 3093) during the period 1990-99. Main outcome measures - Prescription of a new antibiotic drug appropriate for LITI within 4 weeks after the initial treatment was considered as an indicator for a treatment failure. The risk of treatment failure was estimated by calculating the cumulative incidence proportion of new antibiotic prescriptions within 4 weeks after the initial treatment. Results - A new antibiotic followed 8% of sulfamethizole and 9.5% of pivmecillinam treatments. The cumulative incidence proportion of treatment failures did not change during the study period. A logistic regression model showed pivmecillinam to be associated with a higher risk of treatment failure (OR 1.42, CI 1.14-1.77) than sulfamethizole. Conclusion - This study does not support a change in current Danish practice of sulfamethizole being first-line treatment for uncomplicated UVI.