The National Prescribing Service (NPS), Australia's medicine review body, has found that pain relief pills containing a mix of paracetamol and the weak opioid codeine are still preferred by Australians than plain paracetamol despite its side effects and higher price.

In its new review of medicines published Monday in the NPS journal Australian Prescriber, the NPS said most pain relief formulations contain less than 30 milligrams of codeine, the minimum amount for a painkiller to take effect.

Pain killers for toothache, migraine and back pain also contain as little as 8 milligrams of codeine per pill but cost two to three times more, according to the review. One pack of paracetamol costs $2 or less while codeine combinations cost between $6 and $12 depending on strength.

The review concluded that government limitation on codeine preparations would reduce harm to patients without limiting their options.