Research has revealed the extent to which Australian GPs are overprescribing antibiotics for acute respiratory infections.

Australian GPs are overprescribing antibiotics for respiratory infections, even when their use is not recommended, research shows.

Antibiotics are prescribed for acute respiratory infections (ARI) at rates four to nine times higher than recommended by national guidelines, the researchers found.

"The potential for reducing rates of antibiotic prescription and to thereby reduced rates of antibiotic-related harms, particularly bacterial resistance, is therefore substantial," the researchers said.

"Our data provide the basis for setting absolute targets for reducing antibiotic prescribing in Australian general practice."

The researchers led by Bond University public health professor Christopher Del Mar said antibiotic prescribing in general practice could be substantially reduced if GPs adhered more closely to national therapeutic guideline recommendations.

Australians are among the biggest users of antibiotics in the world despite experts here and around the globe warning that excessive or unnecessary use helps more bacteria become resistant to the drugs.

The researchers said their findings, published in the Medical Journal of Australia on Monday, are the first to quantify the overprescribing of antibiotics for ARIs by Australian GPs.

They found an estimated mean of 5.97 million ARI cases per year were managed in general practice with at least one antibiotic.

Had GPs adhered to widely consulted antibiotic prescribing guidelines, they would have prescribed antibiotics for 650,000 to 1.36 million cases a year or 11-23 per cent of the current prescribing rate, they said.

The researchers found GPs are prescribing antibiotics in 85 per cent of acute bronchitis/bronchiolitis cases and 11 per cent of influenza cases, despite guidelines recommending they not be used.

Antibiotics were prescribed more frequently than recommended for ARIs such as acute rhinosinusitis and acute pharyngitis or tonsillitis.

The researchers said diagnostic uncertainty, or a concern by the treating doctor that a serious infection or complication might be missed, is one potential explanation for the oversubscribing of antibiotics.

Antibiotics are always recommended for community-acquired pneumonia and pertussis or whooping cough.