Almost a million Australians are abusing and misusing pharmaceutical drugs, with legal painkillers posing a growing problem, research has found.

Most people taking opioid medication who do not need it for health reasons are sourcing it legally from pharmacists and doctors.

The number of overdoses from prescription painkillers, including opioids, is on the rise in Australia. Credit:AP

More than half the people who abuse painkillers buy them at a pharmacy over the counter, while another 18 per cent usually obtain them with a medical prescription.

The report by the Australian Institute of Health and Welfare found there was a 24 per cent jump in prescriptions for opioid medication in three years to mid-2015, while the rates of the prescription of oxycodone jumped 60 per cent during the same period.