Taking methadone improves the survival chances of drug addicts – but it does not stop them injecting any sooner.

A study carried out by researchers in Edinburgh found that the opiate replacement treatment reduced addicts’ risk of death by 13% in each year they were treated. However, the programme also revealed that being prescribed methadone did not lead to patients cutting back on their drug taking any sooner than they would have otherwise.

The scientists from Edinburgh, Cambridge and Bristol Universities analysed the drug use patterns of almost 800 injecting users in the capital between 1980 to 2007. And they say that despite methadone’s lack of success in ending injecting behaviour, the findings support its long term use as a treatment.

Around one per cent of young adults in the UK are believed to inject heroin regularly. The drug raises a person’s risk of death by more than ten times, and is responsible for a high proportion of overdose deaths each year, as well as for the transmission of HIV and the Hepatitis C and B viruses. A recent outbreak of anthrax in Scotland also caused 13 deaths in injecting drug users.

The researchers found that those prescribed methadone reduced their frequency of injecting drugs, however, the overall number of years of injecting was prolonged in comparison to users not given methadone.

The team also found that a history of imprisonment was associated both with an increased risk of death and a longer duration of injecting. 

Dr Roy Robertson, a general practitioner who led the study at the University of Edinburgh, said: “These results confirm that methadone works and works best when prescribed for as long as is needed in what is a chronic condition.

“The effects of methadone on long-term injection cessation will probably not be particularly surprising for experienced clinicians. Many injectors on a prescription will continue to occasionally inject though may be reluctant to acknowledge this to their doctor for fear of a punitive response.

“Our research shows that despite this they still gain substantial health benefits from their prescription. Suggestions that methadone prescribing should be cut back or confined to the short-term are clearly misplaced and would lead to poorer health for drug injectors.”

A total of 794 people took part in the first part study, with 571 surviving until the start of the follow-up.

Researchers interviewed 75% of the surviving drug users at the end of the study, however, a further five died, bringing the total death rate across the study to 228.