Mismatches between antibiotic pack sizes and the guideline recommendations for their duration is contributing to antibiotic resistance in the community, Australian researchers have found.
Treasure McGuire, Jane Smith and Chris Del Mar analysed existing published information of the most commonly prescribed antibiotics in primary care in Australia, their most common indications, the guideline recommendations for their duration and the duration dictated by antibiotic packaging. The research was published in the Australian and New Zealand Journal of Public Health.
They found that of 32 common antibiotic prescribing scenarios, 10 had doses left over in surplus and 18 had a shortfall.
In only four scenarios did the packaging size match the duration recommended by electronic Therapeutic Guidelines.
Where there was a shortfall, this was only exactly accommodated by a repeat script in two cases.
The researchers say prescribers need to be aware that this mismatch exists, and that it contributes to antibiotic resistance.
“Antibiotics are almost universally packaged by manufacturers in packs that heavily influence duration,” the researchers write.
“This had us speculate on the extent packing size matches the guideline recommendations for duration; any mismatch might contribute to unused antibiotics in the community and, if taken by patients on some other occasion, may contribute to unprescribed use and, thereby, resistance.”
They say that given the mismatch is the rule, rather than the exception, it is likely that a large quantity of antibiotics are dispensed and then not consumed for the prescribed acute illness, contributing to redundant antibiotic doses in the community.
“There are, of course, other contributions to unused antibiotics in the community, including repeat prescriptions (sometimes inadvertently delivered by default settings in general practice prescribing software) and the failure by patients to complete the prescribed course,” they write.
“Nonetheless, our finding represents a problem that is probably more extensive than most prescribers realise.
“It is unlikely that all primary care clinicians follow optimal guidelines in their antibiotic prescribing – this is one of the causes of antibiotic resistance.
“Yet evidence-based guidelines are seen as an important means of changing over-prescribing.
“Even if general practitioners attempt to follow guidelines, difficulties in matching diagnoses and trying to match pack size with recommendations is an important obstacle to their doing so effectively.”
Solutions are not obvious, they say, but do need to be explored “to close off what may be another threat to antibiotic resistance in the community”.