The need to complete a full course of antibiotics has been questioned by experts in the UK, who argue the deeply embedded message puts patients at unnecessary risk from antibiotic resistance.
It's argued in a leading medical journal that there is "little evidence" that supports the idea that stopping treatment early encourages antibiotic resistance.
In an editorial published in the BMJ, Professor of infectious diseases Martin Llewelyn and colleagues at Brighton and Sussex Medical School say its time for policy makers and doctors to drop this message.
They say the "complete the course" notion ignores the fact that different patients respond to treatments in different ways, they said, and added: "Currently, we largely ignore this fact and instead make indication specific recommendations for antibiotic duration that are based on poor evidence.
"This situation is changing in hospital practice, where biomarkers of treatment response can guide when to stop antibiotic treatment.
"Outside hospital, where repeated testing may not be feasible, patients might be best advised to stop treatment when they feel better, in direct contradiction of WHO (World Health Organisation) advice."
For common bacterial infections no evidence exists that stopping antibiotic treatment early increases a patient's risk of resistant infection, the experts said.
Reducing unnecessary antibiotic use is essential to mitigate antibiotic resistance, they argued, adding that antibiotics are a "precious and finite natural resource" which should be given to each patient with a tailored treatment duration.
Associate Professor of Infectious Diseases at the Australian National University Sanjaya Senanayake it's definitely a conversation worth having.
But, he says, says clinical trials to prove a need for much shorter antibiotic courses.
"We don't want to reduce antibiotic resistance at the expense of people getting complications because their infection wasn't treated properly in the first place," Assoc Prof Senanayake told AAP.
"For example Golden Staph in the blood stream we treat for two weeks with intravenous antibiotics because we know if you treat less than that there's a chance it could come back and if it does there's a significantly bad outcome," he said.
The Australian Medical Association (AMA) says there will be no change in prescribing recommendations just yet.
"As more clinical evidence comes into play we will reflect that in our guidelines but we need to be sure we are not doing any harm," said Dr Tony Bartone, Vice President of the AMA.
An entire course of antibiotics doesn't always mean consuming an entire packet and patients should double check with their doctor the length of treatment required, advised Dr Bartone.
"It might be a five day course or a seven day course and you may have a 10 packet and penicillin is one that comes to mind," he said.
