Tighter controls over prescribing have been demanded after new research found that 88% of recovering Scottish addicts who eventually died were taking potentially dangerous anti-anxiety drugs in addition to methadone.
Experts from Dundee's Ninewells Hospital and Medical School and the Royal College of Surgeons in Ireland expressed concern over the fact that 16% of addicts were over-using the heroin substitute by taking more than had been prescribed for them during a 11-year study of 2378 addicts in Tayside.
Some 181 people, or 8% of those studied until February 2004, died and in one in three of those drug dependence was identified as the principal cause of death, the authors of the study found.
But it was the high incidence of co-prescribing of benzodiazepines such as Valium and Temazepam that the authors said was a recipe for disaster, as this was associated with drug-related death. They called for better monitoring.
The report also showed that 77% of those who died had a history of psychiatric admission and nearly half were being co-prescribed anti-depressants.
The report said the study showed the value of "stabilised prescribing" and called for regular monitoring of urine and a prohibition on the co-prescribing of anti-anxiety drugs.
It added: "This community- based study shows that important elements in the process of care when providing methadone maintenance are likely to influence each patient's risk of death. Prescribing of methadone could be improved, particularly as regards dosage, co-prescribing of benzodiazepines, and monitoring."
The study authors, Dr Brian Kidd, clinical senior lecturer in addiction psychiatry at Ninewells Hospital and Medical School; Colin McCowan, lecturer in health informatics at the University of Dundee; and Tom Fahey, former professor of primary care medicine at the University of Dundee, said the report showed drug deaths were associated with co-prescription of benzodiazepines and history of psychiatric admission. They said the study showed the need for a "psychosocial perspective" for those on methadone maintenance programmes.
The Scottish Government says five people die every day in Scotland from drink and drug abuse, which costs Scotland an estimated £5bn a year.
It is estimated that more than 20,000 drug users are receiving methadone in Scotland.
Last year it was claimed that Scotland's war on drugs was a failure as figures revealed the level of drug-related deaths had doubled in the past decade.
Official statistics from the General Register Office for Scotland showed 455 such deaths in 2007 - a record number - with 25% involving methadone.
Many health experts officially advise against the prescribing of methadone and benzodiazepines as it increases the effects of the drugs and there is an increased risk of overdose. The mixture can send patients into a sleep so deep that they stop breathing and die.
A survey by the Scottish Drugs Forum (SDF) in May found that more than half of its treatment services raised concerns about the use of Valium.
The use of benzodiazepines boomed in the 1960s as a supposedly safe alternative to barbiturates, but GPs subsequently reined back on prescribing them following evidence of significant side-effects including addiction.
Of the 37 different Scottish Drugs Forum treatment services across 13 local authority areas, eight said there was an increase in the street availability of the drugs, known as "blues" or "vallies", and a further eight reported an increase in people mixing benzodiazepines with heroin, methadone and alcohol.
There has been widespread concern that the vast majority of addicts on the £6.5m-a-year heroin-replacement programme in Scotland are still taking illegal drugs years later.
In the latest study, researchers found more than 40% of patients were prescribed methadone for more than three years and just over half were still on treatment at either the date of death or the end of the study more than 11 years later.
"Overuse of methadone may be a marker of less rigorous follow-up and communication between prescribing general practitioners and dispensing community pharmacists," the analysts added.
Exclusive by Martin Williams
Source - http://www.theherald.co.uk/news/new...as_methadone_mixing_linked_to_drug_deaths.php