Almost 80 per cent of pharmacotherapy clients in the ACT were treated with methadone on a snapshot day in June 2014, with the remaining clients treated with buprenorphine either alone or in combination with naloxone.

The Australian Institute of Health and Welfare report found 48,000 Australians were on a course of pharmacotherapy treatment on the random sample day.

Pharmacotherapy treatment is often used to reduce a client's cravings for opioids, to improve their physical and mental health, and to reduce drug-related crime.

AIHW spokesperson Geoff Neideck said the number of people using methadone to treat their drug dependence was steadily increasing.

"Between 1998 and 2010 the number of people receiving opioid pharmacotherapy treatment increased by an average of two per cent each year, but this dropped to two per cent between 2013 and 2014," he said.

Mr Neideck said the latest data indicated the median age of opioid pharmacotherapy clients had increased and that males and Indigenous people were over-represented.

"About two-thirds of clients receiving pharmacotherapy were male, and around one in 10 clients identified as Aboriginal and/or Torres Strait Islander," he said.

The AIHW report was published on the same day as drug experts at the Penington Institute called on the federal government to subsidise the dispensing of medicines that help people get off heroin and pharmaceutical opioids.

Now, people prescribed pharmacotherapy drugs such as methadone and buprenorphine receive them free under a federal government scheme.

But most pharmacists charge between $1 and $10 a day for it to be prepared and dispensed inside a pharmacy. This is done so the pharmacist can ensure the safety of the patient after their dose and to check it is not being taken away to sell on the black market.

Chief executive of the Penington Institute John Ryan said these dispensing fees meant some people, including low-income earners, were paying up to $75 a week for their medicines.

In comparison, he said a person with type-2 diabetes who had a Healthcare Card and used a commonly-prescribed insulin, paid around $70 a year for it.

The Penington Institute report calls for the federal government to subsidise pharmacists for daily dispensing so patients do not have to pay for it out of their own pocket.

Under its suggested model, people could pay $36.90 per monthly prescription, or $6 if they have a Healthcare card – the same co-payment people currently pay for medicines listed on the Pharmaceutical Benefits Scheme.

A spokeswoman for the federal health department said the Commonwealth was already spending $49.1 million to cover the full cost of treatment for people with opiate dependence and that dispensing fees were a commercial decision for pharmacists.

Health Minister Sussan Ley would not comment on whether the government would consider covering the dispensing fee.