The misuse of prescribed pharmaceuticals is Australia's fastest growing drug problem, raising the possibility that deaths from prescribed drugs may eventually surpass those from illicit drug overdoses, doctors have warned.

Structural issues in the health system, including limitations of GP consultations and rapid hospital discharges, are contributing to an explosion in prescriptions for opiods, benzodiazepines and codeine-containing analgesics.

These drugs are being diverted for non-medical use by unwell people seeking to supplement low incomes, while doctors also report that young people are increasingly initiating drug use with their parents' left-over scripts for pain killers, sleeping pills or stress-reducing drugs.

Between 2002 and 2006, the use of legal narcotic drugs in the United States increased by 60 per cent and consumption of pharmaceutical amphetamines rose by 42 per cent. According to the US Centre for Disease Control and Prevention, poisoning deaths involving opiod analgesics including oxycodone, methadone and hydrocone more than tripled from 1999 to 2007.

The data suggests Australia is on ''a similar trajectory'', said the lead architect of the federal government's national pharmaceutical drug misuse strategy, Professor Ann Roche.

The trends, which have also been seen in Europe and Canada too, are so strong that it is likely ''the misuse of pharmaceuticals may displace black market drugs as one of our biggest drug problems'', warns Professor Roche, who is also director of the National Centre for Education and Training on Addiction at Flinders University.

In 2008, per capita use of oxycodone, often sold in Australia as OxyContin and prescribed for moderate to severe pain, reached 60 kilograms per million population, eight years after the US reached this level. Studies reveal an exponential increase in the total supply of oxycodone to Australia, from 95.1 kilograms in 1999 to 1620.3 kilograms in 2010, along with substantial increases in harm episodes and deaths.

In metropolitan Melbourne last year, the highest number of drug-related call-outs after alcohol was for benzodiazepines, a drug commonly prescribed for sleeping and anxiety issues.

Professor Roche said there was a high level of prescribing of opiates as the first line of treatment for chronic, non-malignant (non-cancer) pain which was ''not always appropriate''. The push for rapid discharge of patients from hospitals meant many people left with large amounts of opiods or scripts for them.

With a tab of oxycodone selling on the black market for $50 to $100, a phenomenon of ''use a little, sell a little'' had arisen, Professor Roche said.

''Some people with a legitimate health problem can supplement their income or pension by on-selling their drugs, because there is such a high demand for them.''

GPs needed better training and support to treat pain using non-drug therapies, and there was a great need for more multi-disciplinary pain management clinics, the president of the Australian Medical Association, Steve Hambleton, said.

But the community thinks and expects that there should be ''a pill for all ills'', and they should not have to suffer any physical or psychological pain, said the director of the Turning Point Alcohol and Drug Centre in Melbourne, Professor Dan Lubman.