Looming prescription medicine changes will result in poorer health outcomes for regional Australians, Nationals leader David Littleproud warns.

Measures coming in from September 1 will allow patients to access 60 days' worth of medicine from a single prescription, replacing the current 30-day limit.

The federal opposition launched an unsuccessful bid in parliament to overturn the laws, saying community pharmacies would be financially affected by the changes due to reduced dispensing fees.

Mr Littleproud said the changes would be felt in regional communities in particular.

"If you change that business model by going from 30 to 60 days, then that has a fundamental change on those small businesses and particularly for those young (pharmacy owners) that have just got into this," he told ABC Insiders on Sunday.

"If we lose this, we lose that last line of primary care.

"There will be perverse health outcomes and I fear regional and rural Australians' lives will be put at risk."

Mr Littleproud said regional pharmacies would be at risk of closing under the changes and urged the government to sit down with the Pharmacy Guild to discuss the issue.

"It might sound great to have a few dollars in your pocket living in Canberra and you can run from one suburb to the next to see a pharmacist, but in some of the towns I represent, they could be four or 500 kilometres away from any primary care," he said.

"This is an opportunity for political leadership, for political courage and common sense."

The coalition has called for the government to fund the proposal to protect community pharmacies.

Health Minister Mark Butler said the estimated $1.2 billion in savings from the measure across the next four years would be reinvested in community pharmacies.

"In the three months since I've announced this measure, there have been twice as many applications for new pharmacies to be opened," Mr Butler said last week.

It is estimated the prescription changes will halve the cost of 320 common medicines for about six million Australians.

The opposition is expected to launch a fresh attempt to wind back the prescription changes when parliament resumes next month.