Heroin addicts who detox more likely to die of an overdose

Heroin addicts who successfully complete detoxification programmes to get off the drug are at increased risk of dying from an overdose if they then relapse, researchers warn today.

Five addicts died within 12 months of being discharged from the in-patient unit at the National Addiction Centre based in the Maudsley Hospital, London, three from overdoses and two from other causes.

The deaths raise a question about the safety of the detoxification treatment that is provided in 156 in-patient units around the country plus a large number of out-patient and community based programmes.

Professor Michael Gossop from the research team blames progressive cuts in the length of rehabilitation programmes. "To some extent these are victims of an inadequately funded service," he said yesterday.

Addicts are known to be at greater risk of overdose after treatment or enforced withdrawal in prison because their tolerance to drugs is reduced. Years of daily use builds up tolerance so a larger dose is needed to achieve the same high.

Professor Gossop said: "The apparent paradox in our study was that the more successfully addicts had been treated, the more likely they were to have an overdose. When we followed them up we found more of them had died."

David Blunkett, the Home Secretary, said in January he was considering introducing compulsory treatment for drug users, in an effort to cut crime.

About 120,000 people a year go through drug rehabilitation programmes every year at a cost of £2,500 for a basic programme. Government spending on drug treatment programmes was £236m last year. But Professor Gossop said: "Treatment services have been cut back over the past decade so many services are running shorter programmes. But detoxification does not constitute treatment for addiction – it is what happens afterwards that determines success. When you think of the changes an addict has to make, it is pretty difficult to achieve in 28 days. We have done studies showing treatment programmes of less than 90 days are significantly less likely to be effective."

The researchers, whose findings are published in today's edition of the British Medical Journal, studied 137 opiate addicts who were receiving detoxification as part of a 28-day in-patient treatment programme. They found that 37 of the addicts who had completed the programme had lost their tolerance to heroin, putting them at greater risk of overdose when they took another dose of the drug. A further 57 who left the programme early had reduced tolerance and the remaining 43 who failed to complete detoxification were still tolerant.

Four of the five deaths occurred in the most successful group who had lost their tolerance to heroin and the fifth occurred in the "reduced tolerance" group. There were no deaths among addicts who failed the programme and were still tolerant. The authors say: "The clustering of deaths from overdose in patients who had successfully completed treatment is counter-intuitive and illogical – unless it relates to loss of tolerance and consequent unpredictability of resumed heroin use ... If these results are confirmed they will need to be addressed within existing in-patient ... and associated aftercare programmes."

Professor Gossop said: "Many drug services are reluctant to discuss relapse. Psychologically it is a time when you want to be optimistic. But warning about the risks of overdose is something a responsible service ought to be doing."