Prescription charges will increase from $3 an item to $5 an item in next week's Budget, as the Government moves to offset the cost of extra health spending in the "zero Budget".

The new charge will cover up to a maximum of 20 items from January 1 next year, raising $20m in the first year and $40m after that.

Health Minister Tony Ryall and Prime Minister John Key said the money raised would be reinvested in the health sector.

"Despite tight financial times and what will be a zero Budget on May 24, health will receive a big funding boost, which will come from savings within health and across the Government's accounts," Ryall said.

It was the first time the prescription charge has been increased in 20 years. There will continue to be no charge for under-sixes.

In a pre-Budget announcement Key and Ryall said the Budget would fund four initiatives.

A further $48m would go to increase elective operations by at least 4000 each year.

"We also want shorter waits for important diagnostic tests, such as MRI scans, CT scans, and colonoscopies. These tests help determine if patients require an operation or other treatment."

Another $16m would go on IT systems to speed up access to those tests, and $4 million for a national register of patients treated for heart conditions, to improve the quality of care across hospitals.

The Budget would also deliver an additional $33m over the next four years for better and faster services for cancer patients.

This included funding for dedicated nurses to co-ordinate care and support for individual patients throughout the course of their cancer treatment.

"This more personalised service will mean better treatment and a less stressful experience for patients," Ryall said.

"Research shows some cancer patients can come into contact with up to 28 doctors and even more nurses throughout their treatment. The new dedicated cancer nurses will act as a single point of contact and assist patients and their families across different parts of the health service. This expands what is already happening in parts of the country and feedback from patients has been fantastic.