MEDICAL MATTERS: Debate over heroin prescription needs to reopen, writes MUIRIS HOUSTON
HERE IN downtown Vancouver you quickly become aware of a particular group of older men on the streets. Slightly down at heel, many with beards and ponytails, they have a far-away look in their eyes. I’m told many are military refuseniks, who crossed the border into Canada rather than serve with the US army in Vietnam. These are the guys who never went back. Instead, they settled in British Columbia and availed of its relaxed marijuana laws, perhaps as a way of salving separation from friends and family. But prolonged use of pot has left them more wizened and dazed looking than their peers.
Drug laws are relaxed in the Canadian province. On my last visit, I overheard a conversation between a petrol station owner and another customer, during which they discussed the relative quality of their marijuana crops. The approach to drug addiction differs in other ways, too, as research published in the New England Journal of Medicine last year revealed.
Heroin is a hard drug of abuse, with often fatal consequences. The risks of heroin dependence include fatal overdoses, infections (including HIV and hepatitis C), social disintegration, violence and crime. In turn, this brings with it medical, public health and criminal justice costs.
Surprisingly, perhaps, in 1920s Britain, GPs and psychiatrists were allowed to prescribe maintenance doses for people – mainly from the middle classes – who could not shake off their heroin addiction. It is still legal to prescribe it in the UK, where it is used to treat a small number of patients. But the majority of heroin addicts – including those in the Republic – are now treated using methadone, a heroin substitute, which has produced both health and social benefits.
Methadone has been shown to reduce major risks associated with untreated opioid dependence in patients who are willing to undergo treatment. However, 15-25 per cent of the most adversely affected addicts do not have a good response. Either they don’t stay in methadone maintenance programmes or they continue to use illicit opioids while in treatment. European studies have suggested that injectable diamorphine, the active ingredient in heroin, can be an effective alternative maintenance treatment for these patients.
In the Canadian study, doctors compared injected heroin with oral methadone maintenance therapy in patients who had not responded to the standard treatment regime. They found a much higher rate of addicts sticking with treatment on the heroin programme. The retention rate for those given injectable heroin was 88 per cent, compared with 54 per cent in the methadone group.
So why isn’t heroin used in heroin addiction programmes? Well, to begin with, it is illegal to prescribe or market it in the Republic. But even in countries where it remains an approved drug, its bad name means it has moved from being seen as an acceptable medical treatment to killer drug. When added to differing national attitudes to treatment and heroin prescription, it meant that oral methadone emerged as a more socially acceptable treatment in the 1960s and 1970s.
It seems the rise and fall of methods of treatment in this controversial area owe their rationale to evidence, but perhaps even more to the politics of the situation. Bluntly, it may come down to which interests are prepared to support or oppose it. The “harm reduction” treatment model associated with methadone maintenance is undoubtedly being questioned, with one sceptic describing it as “methadone, wine and welfare”. As part of a redefinition of the purpose of treatment, the dominant role of methadone as “the only show in town” may change.
Doctors and legislators must face up to the fact that there is a significant minority who will never benefit from optimum methadone maintenance. Is it time to cast aside the stigma of heroin prescription and accept that, as in other branches of medicine, it is usual to have a recognised second-line treatment to turn to in selected patients?
mhouston@irishtimes.com