General Practitioners (GPs) are prescribing antibiotics for up to 80% of sore throat, otitis media, upper respiratory tract infections, and sinusitis cases, despite the fact that official guidance warns against this practice, according to an analysis of the world’s largest primary care database of consultations and prescriptions, published this week in a supplement to the Journal of Antimicrobial Chemotherapy.

Although prescriptions of antibiotics for respiratory tract infections declined during the 1990s, GPs still continue to prescribe antibiotics for a high proportion of infections even if the cause of the symptoms are likely to be viral. And this practice is hindering efforts to prevent the spread of antibiotic resistance - whereby disease-causing bacteria become unresponsive to the most commonly used drug treatments.

“Many doctors believe that by giving an antibiotic they might be doing some good or at least covering the possibility of a missed diagnosis of significant bacterial disease, with little thought given to the possibility of doing harm,” explains Douglas Fleming, a GP and member of the UK’s Specialist Advisory Committee on Antimicrobial Resistance, a government advisory body, in an accompanying perspective article.

The study attempted to assess antibiotic prescribing in primary care by use of the General Practice Research Database of consultations and prescriptions. The researchers searched for all consultations between 1998 and 2001 for conditions that might have resulted in an antibiotic prescription. They then identified prescriptions for antibacterial drugs issued by 60 GPs on the same day as a consultation that had identified a possible antibiotic-treatable condition. If an antibacterial was prescribed on the same day as a possible antibiotic indication, it was assumed that the drug had been prescribed for that purpose.

The ten most common causes of antibacterial prescribing identified in the study were: upper respiratory tract infection, lower respiratory tract infection, sore throat, urinary tract infection, otitis media, conjunctivitis, vague skin infections without a clear diagnosis, sinusitis, otitis externa, and impetigo. The researchers found that for some of these conditions over 80% of cases were being treated with antibiotics, despite the fact that guidance recommend against antibiotics for sore throat, otitis media, upper respiratory tract infections, and sinusitis.

Regular analysis of the data should be done to monitor trends in GP prescribing, which are known to have plateaued since 2001, suggest the authors. According to a review4 of professional attitudes to antibiotic prescribing, published as part of the supplement by the professional education subgroup of the Specialist Advisory Committee on Antimicrobial Resistance, GPs and other prescribers must be educated about how to dispense treatment appropriately and avoid adding to the problem of resistance.

“We must not be lulled into a false sense of security believing the prescribing behaviour of GPs has changed. It is preferable to focus interventions on changing behaviour rather than trying to persuade doctors from evidence of the link between resistance and inappropriate prescribing,” comments Dr Fleming.

One of the most important determinants of whether or not a patient receives a prescription for antibiotics is if they have had previous prescriptions for that condition. Clinicians report that they often prescribe antibiotics because they perceive that patients want them. To investigate the effect of patient awareness of antibiotic resistance on prescribing patterns, a multicentre team sponsored by the Department of Health surveyed public attitudes to antibiotics in a separate study5 published in the same supplement.

38% of the 7120 respondents reported that they had been prescribed an antibiotic in the last year. However, the survey found a surprisingly high proportion of people believe that antibiotics work on viral conditions and found that a greater knowledge about antibiotics and when they should be used was not associated with a lower likelihood of being prescribed an antibiotic in the last year. The study also found that awareness of how antibiotics should be used did not necessarily correspond with appropriate behaviour. For example, individuals who said they knew that a course of antibiotics should always be completed also remarked that they would keep left over antibiotics to use on another occasion.

“Although a third of the public still believe that antibiotics work against coughs and colds, simply getting the public to believe otherwise may not be enough to reduce the level of prescribing. We have shown that those with greater knowledge about antibiotics are no less likely to be prescribed an antibiotic,” comment the report’s authors.

How to communicate messages about the risk of drug resistance will become more pressing in future because resistance to antiviral drugs - as well as antibacterials - is a growing concern, according to Dr Deenan Pillay, who authored an essay about priorities for antiviral drug surveillance in the supplement.6

“The emergence of antiviral drug resistance is virtually inevitable. This provides a major clinical, laboratory, and public health challenge. We have already learnt the potential for spread of these viruses from experience with HIV. A coordinated approach is required to ensure that the clinical benefit afforded by these drugs is maintained,” he warns.

All the essays for the supplement relate to the work of the Specialist Advisory Committee on Antimicrobial Resistance (SACAR), a body that was set up in 2001, under the Chairmanship of Professor Richard Wise, to advise ministers and the Chief Medical Officer on current and emerging problems in antimicrobial resistance. The committee was charged with helping to minimise emerging antimicrobial resistance and its possible impact, while ensuring that measures are in place in a timely manner to meet threats to clinical management. The SACAR is now standing down to make way for a new body, the Advisory Committee on Antimicrobial Resistance and Associated Health Care Infections, to be headed by Professor Roger Finch.

Source: Oxford University