Many heroin addicts could be helped by a programme which includes the drug itself alongside conventional treatments, say researchers.
There is controversy over the use of heroin as a treatment
Although the idea of giving the drug which is the root cause of the addiction is still fiercely opposed by some, evidence is increasing that some users could benefit.
The latest study, carried out in the Netherlands and published in the British Medical Journal, involved more than 500 patients described as "treatment resistant" - they had all been using heroin for at least five years.
The aim of the treatment programme was to improve their physical and mental health, and reduce social problems such as their criminal activity.
Some of the addicts were given a combination of either inhalable or injectable heroin plus methadone - the customary drug given to reduce the unpleasant effects of heroin withdrawal.
They were compared with patients given methadone alone.
Up to a quarter of those treated with the combined prescription were assessed as having responded well over a 12 month period.
This compares with just over 10% of those on the methadone only regime.
However, the figures reveal the difficulties in treating heroin users - a sizeable majority failed to respond to either programme.
Possible way forward
The study's authors say that despite its limitations, the prescribed heroin study shows that the drug is safe when given under medical supervision, and perhaps a good deal more effective than current strategies which rely on methadone.
In the UK, there are no plans to allow heroin prescribing to users, although leading figures in law enforcement say it would significantly reduce certain types of crime which are driven by the need to fund an expensive drug habit.
Gerry Stokes, Director of Operations for Addaction, one of the leading agencies working with users, said it was not necessarily a bad idea.
He said: "We are not involved in prescribing heroin to dependent users, and we do not have any plans to do so in the future.
"The idea of harm reduction is not understood or necessarily welcomed by many people outside the drug field.
"However it is a vital tool in protecting the health of injecting drug users from communicable diseases.
"We are therefore open to the argument that regulated heroin prescribing could be a useful way of reducing harm.
"At the same time we recognise that if people were ever to be offered heroin, it must happen in an environment that is carefully controlled and regulated - similar to the prescribing system that currently exists."