More than 400 prescription medicines for conditions ranging from cholesterol to high blood pressure have dropped in price this week.

Consumers will save around $20 each prescription after the Government's Pharmacy and Pharmaceutical Benefits Scheme changes came into force.

The renewed agreement cuts the cost of production of some of the nation's most commonly-prescribed drugs.

The price change comes as a result of patents covering the chemical makeup of the drugs expiring, which this year includes medications to treat leukaemia and cardiovascular disease.

Health Minister Sussan Ley says over 400 medicines are dropping in price, four times the number at the same time last year.

“This is not about [the] Government adding money into the PBS, it's actually about consumers benefitting because the manufacturers of medicines are now being paid less,” Ms Ley said.

“Part of our agreement for price reductions now has been the cost of expensive combination medicines that have been priced too highly in the past.

“If you combine two generic molecules, it's not appropriate to call them a brand new medicine — in fact they should reflect the price of their components.

“For the number of Australians now who live with chronic and complex disease, and may take several medicines a month, this is really good news.

“When it comes to ongoing reductions in price, all drugs are in the spotlight because as they come off patent and they come generic, they all start to reduce in price.

“Those that the Government subsidises on the PBS are especially in the spotlight when it comes to this, because we know that if we can continue to reduce the price that [the] Government pays, we can make room to list more medicines.”