Antibiotic-resistant bacteria are a threat to global health, the World Health Organization has said. Overusing and overprescribing antibiotics is partly to blame, with urinary tract infections (UTIs) being one of the most commonly overprescribed conditions. But a new study published in CMAJ (Canadian Medical Association Journal) says not all antibiotics are cause for concern.

The study involved 71 physicians from 30 general practices apart of The Irish Primary Care Research Network, and it was carried out in three phrase: Phase 1 invited all general practitioners to an interactive coding workshop, where they learned (among other things) the importance of consultation coding for the generation of doctors' audit reports. And during the second phase, practitioners were split into groups, where Group A received information on national guidelines for antimicrobial prescribing and Group B received both guideline information and additional evidence to support delaying antimicrobial prescription for suspected UTIs.

These groups also received monthly audits of antimicrobial prescribing for UTIs; a third group acted as a control and only attended the workshop.

In the final phase of the study, researchers introduced practitioners to a multimedia application that included a game for children and an infomercial for adults addressing antimicrobial awareness — both made accessible to patients in the physicians' offices. Then, after six months, the control group received these same materials, as well as respective audit reports.

Antimicrobial prescribing did not differ among groups during the study's baseline, and a first-line (first-choice) antimicrobial agent was prescribed between 45.4 and 49.8 percent of UTI consultations, researchers said. But by the end of the intervention period (when practitioners were split into groups), the rate of first-line prescribing was 68.2 percent in Group A (increased by 22.8 percent), 66.5 percent in Group B (increased by 16.7 percent), and 44.1 percent in the control (a decrease by almost 2 percent).

When compared to the control group, researchers found the absolute increase in first-line prescribing was 24.5 percent in group A and 18.4 percent in group B. These prescription rates were higher when considering nitrofurantoin, one of the antimicrobials women are recommended they take first.

"The focus of our intervention was on increasing the proportion of antimicrobial prescriptions for nitrofurantoin," researchers wrote. "…Patients visiting an intervention practice were up to five times more likely to receive a prescription for nitrofurantoin than any other antimicrobial. However, the improved quality of prescribing must be put into the context of its unintended effect, an increase in actual antimicrobial prescriptions."

Researchers added prior studies have shown general practices, given their complex systems, make it difficult to predict results of interventions like these; there are so many factors to consider. Yet, they seem to agree if antibiotic prescribing is the result of an increase in nitrofurantoin, then antimicrobial resistance may be less of a concern.

Nitrofurantoin has been extensively used worldwide for more than 50 years and is currently "prescribed almost exclusively for patients with suspected UTI." Researchers said there has "been little evidence of acquired resistance to nitrofurantoin" and taking this antibiotic "does not appear to predispose patients to resistance." This suggests it "may be less harmful than and much preferred over other antimicrobials."

They concluded: "The reduction in repeat consultations (a proxy for treatment failure and thus antibiotic resistance) among patients who received nitrofurantoin, but not in the intervention arms overall, suggests that improving adherence to prescribing guidelines leads to better patient outcomes."

Source: Vellinga A, et al. Intervention to improve the quality of antimicrobial prescribing for urinary tract infection: a cluster randomized trial. CMAJ. 2015.