High dose antibiotics curb resistance surge
GP prescribing of short, high-dose courses of antibiotics can curb surging rates of drug-resistant infections, researchers report.
A series of new studies of UK primary care reveal GP prescribing of antibiotics is driving up resistant urinary tract infections, C. difficile and MRSA, writes Emma Wilkinson.
But the short, sharp shock approach to use of antibiotics appears to reduce the impact on resistance rates, one of the studies suggests.
The University of Cardiff study found use of amoxicillin prescriptions of seven days or longer in the past month increased the risk of resistant UTIs four-fold.
Similar length courses over the previous two to three months more than doubled risk of ampicillin-resistant UTIs, according to the study, to be presented to the Health Protection Agency annual conference in September.
But high doses of amoxicillin were associated with a lower risk of resistant infection,
the analysis of 932 patients with laboratory-confirmed UTI found.
Study leader Dr Sharon Hillier, specialist trainee in public health at the University of Cardiff, said: 'High-dose, shorter duration antibiotic regimens may be an effective method in helping prevent further increases in antibiotic resistance.'
Antibiotic prescribing is also linked with increasing rates of other resistant infections in the community, report two studies to be presented at the International Conference on Pharmacoepidemiology and Therapeutic Risk Management in Lisbon at the end of this month.
An analysis of the UK general practice research database by Canadian researchers found the risk of MRSA in the community was increased four-fold in patients who had been given four or more prescriptions in the past year.
The same research group also found antibiotics except tetracyclines increased risk of
C. difficile infection in the community.
Patients prescribed a seven-day or longer course of trimethoprim in the previous month were at an eight--and-a-half-fold increased risk.
Professor Paul Little, professor of primary care research at the University of Southampton, said: 'Small doses of antibiotics over a longer period is a recipe for resistant bugs.
'The conclusion about shorter [and higher] doses is interesting and does make sense but would need to be confirmed as it is presumably a secondary analysis,' he said.