The new prescription drug plan will be voluntary this year, but will become mandatory next year. (iStock)

An expert on public drug policy in Canada says he is concerned about the high premiums New Brunswickers will have to pay through the new provincial drug plan.

The plan, which begins on May 1, will cover the estimated 70,000 families who don't have insurance through their employers, or don't qualify for existing provincial coverage for those on social assistance.

Premiums will be based on income, ranging from $800 to $2,000 per year.

"It's good to have coverage for everybody, but this type of coverage with this type of co-payment in the end remains very, very problematic for me," said Marc AndrĂ© Gagnon, assistant professor at the School of Public Policy and Administration at Carleton University in Ottawa.

In Quebec, the maximum premium an individual can pay is $595 a year, said Gagnon.

In New Brunswick, there will also be a 30 per cent co-pay for drugs at the pharmacy to a maximum of $30 per prescription.

"We have this new plan coming in order to provide better access, but with such high co-payments, still a lot of people [are] not getting the drugs they need because the out-of-pocket costs for them will be just too high, too expensive," said Gagnon.

Last week, Health Minister Ted Flemming told CBC News the premiums will decrease over time.

"Premiums go down when the critical mass of participants expands. We have every reason to expect our premiums to go down in the second phase," Flemming had said.

The plan will be voluntary this year, during phase one, but will become mandatory next year during phase two.

Small business owners have expressed concerns about the premiums employers will have to pay in the second year.

The provincial government is still working out details about how business owners will contribute to the plan, Flemming said.

The plan will cover any prescription drugs that are on the provincial formulary, a list of covered drugs. That list includes some so-called catastrophic drugs like Remicade, but does not include others.