Pharmacists are being told to dispense only one month's worth of prescription medicines and limit the purchase of some over-the-counter products from today.

Key points: Over-the-counter medicines, like Ventolin and paracetamol, will be limited to one unit per person

Over-the-counter medicines, like Ventolin and paracetamol, will be limited to one unit per person Pharmacists will be required to keep children's paracetamol behind the counter

Pharmacists will be required to keep children's paracetamol behind the counter The deputy chief medical officer says while there's no shortage, there is a strain on supplies

The deputy chief medical officer Paul Kelly said there was no medicine shortages in Australia but unprecedented demand was putting a strain on supplies.

He said pharmacists were also being told to limit over-the-counter medicines like Ventolin and paracetamol to one unit per person.

"There have been reports of people buying large quantities of these medications over the last few days," Dr Kelly said.

"I recognise again that people are fearful about issues, particularly those that might affect their own families.

"But I say again, as the Prime Minister said yesterday about panic buying, please do not buy more than you need."

Pharmacists will be required to place some medicines, including children's paracetamol, behind the counter to tackle panic-buying.

Dr Kelly insisted that, while there had been localised cases of medicines in short-supply, Australia was well stocked nationally.

Senior federal ministers have been pleading with shoppers to stop hoarding food, staples and household products.

Prime Minister Scott Morrison dubbed it "un-Australian" and demanded people "stop it" on Wednesday.

Dr Kelly called for calm in pharmacies and beyond as Australia responds to the coronavirus.

"It is not OK to be abusing people who are teaching our kids. It is not OK to be abusing people and being angry at people at Woolworths and Coles," he said.

"It is not OK to be angry at people trying to do their best in healthcare.

"This is a time for us to be working together and to be the best people we can in Australia."