Around 15% of antibiotic courses prescribed by GPs for common infections fail, a rate that has risen markedly in recent years alongside a rise in prescriptions, a study in the BMJ has reported.
The authors called for closer monitoring of antibiotic failure in primary care and for GPs to take more care to prescribe recommended first-line antibiotics.
The study – backed by Abbott Healthcare – considered nearly 11 million prescriptions of first-line antibiotics for four common infections over the period 1991 to 2012, using data from the UK Clinical Practice Research Datalink.
The researchers found antibiotics failed in 13.9% of episodes in 1991, rising to 15.4% in 2012. The vast majority of these were identified by evidence of a switch to an alternative antibiotic, while just under 5% were flagged because the patient was referred to an infection-related specialist clinic.
The failure rate was higher for lower respiratory tract infections, rising from 16.9% to 21.0% over the study period, with a big increase in cephalosporin failure seen in particular.
Trimethoprim failure when used for upper respiratory tract infections was also high, rising from 24.7% to 55.9% in 2008-12, whereas failure rates for flucloxacillin in skin and soft tissue and macrolides in general remained largely stable.
The researchers said the increase in treatment failure coincided with a rise in the proportion of consultations in which an antibiotic was prescribed, which went up from 64% to 66% between 1991 and 2012, with a temporary fall to 61% in 2000.
The authors concluded: ‘Our data suggests that primary care physicians could play a central role in helping to contain rises in antibiotic treatment failure by managing patients’ expectations and carefully considering whether each prescription is justified; once the decision is made to prescribe an antibiotic, the choice should follow current guidelines regarding first-line drugs.’
Lead author Professor Craig Currie, from the Cochrane Institute of Primary Care and Public Health at Cardiff University, said: ‘Antibiotic resistance in primary care needs to be more closely monitored, which is actually quite difficult given that primary care clinicians seldom report treatment failures.
‘The association between antibiotic resistance and antibiotic treatment failure also needs to be further explored. From the general level of feverish debate, it’s not quite the “cliff” we would have imagined, but clearly this is worrying.’