Some of Australia's sickest people will pay more each year for their medicines due to a little-noticed change in last week's federal budget.

Health Minister Sussan Ley on Monday announced an agreement with the Pharmacy Guild which she said would deliver "cheaper, more affordable medicines for consumers", partly because pharmacies will have the option of cutting the patient contribution by $1 per script.

Health Minister Sussan Ley. Credit:Alex Ellinghausen

However, from January the government proposes to increase the amount patients have to pay each year before they qualify for free or more heavily discounted scripts under the Pharmaceutical Benefits Scheme safety net.

Currently, after general patients spend $1453.90 in a year on PBS medicines, they get further scripts for the rest of that year for $6.10 each. Under the budget proposal, this threshold will be increased by 10 per cent each year for four years, in addition to indexation in line with the consumer price index, eventually adding several hundred dollars to the amount patients must spend before qualifying for relief.