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The keys to the prison of opiate addiction

Julia Black
RGN CPN
Community Psychiatric Nurse Northern General Hospital
Sheffield

According to the Department of Health, drug services and GPs treated 118,500 clients with substance abuse problems during 2000/1. Between October and March 2001, drug services and GPs instigated 33,200 "new treatment episodes". Sixty-seven per cent of the new clients used heroin. Of these, 55% injected the drug. The remainder smoked heroin (otherwise known as "chasing the dragon").(1)
Of course, many more people use heroin than present to drug services. Indeed, around 2% of men and 1% of women try heroin at some time.(1) Most casual users need to take heroin for several months before becoming dependent,(2) so fortunately, fewer people - perhaps 200,000 - are problematic opiate users.(1) Nurses need to emphasise to patients that using opiates for analgesia rarely leads to addiction. In one study, only two of 38 outpatients taking oral opioid analgesics for noncancer pain developed craving and needed increasing doses. Both patients had previously abused drugs.(2)
In dependent people, opiate use tends to wax and wane. Relatively few heroin users take opiates daily. Indeed, many users stop using opiates for a time - sometimes for more than a year - even once physical dependence develops. Nevertheless, opiate addiction is often chronic. In one study, 41% of men who underwent treatment for their addiction 33 years previously reported using heroin during the preceding year.(2)
Many opiate users turn to crime to support their habit. A typical opiate user spends more than £16,000 annually to support his or her use of illicit drugs. On average, criminal activities supply about £13,000 of the funds that an addict needs.(1)
As a result, managing the health and social consequences of drug abuse imposes a heavy economic burden. The Audit Commission estimated that during 2002 the government spent some £3.5 billion trying to tackle drug-related problems. Treatment comprises a relatively small proportion of this - the government plans to invest some £573 million in treatment during 2005.(1)
Opiate addiction is associated with considerable indirect costs arising from, for example, reduced productivity. Many opiate-dependent people find holding a job difficult and, tragically, many addicts die prematurely because of their drug abuse. Each year, 1.5% of chronic heroin users die from overdoses and other drug-related causes or from the accidents and violence that are an almost inevitable consequence of their lifestyle. In 2000 alone, for instance, almost 1,000 people in the UK died after overdosing on opiates.(1)

Methadone: still the mainstay of management?
Although opiate use varies over time, many patients find protracted abstinence difficult, if not impossible. Substituting opiates with methadone, which is usually given orally, aims to attenuate withdrawal, reduce drug consumption, move patients away from injecting drugs and counter criminal activity.(1) This is the so-called maintenance phase. As the drug-free lifestyle develops, clients can gradually reduce their opioid use until they abstain. Addiction services refer to the latter phase as detoxification or withdrawal.
Since the early 1970s, methadone has helped wean numerous addicts off illicit opiates. Indeed, residential and community programmes using methadone more than double abstinence rates and halve the number of clients that regularly abuse opiates.(3) Nevertheless, only around 20% of people with problematic heroin use currently use methadone.(1)
The National Treatment Outcome Research Study (NTORS), which followed 1,075 clients for up to five years, exemplifies the benefits of treatment. Three-quarters of the clients enrolled in NTORS used heroin at least weekly, although 81% used at least two illicit drugs and over a third were problem drinkers.(3) Ironically, a recent textbook notes, "from a medical standpoint, ethanol is a far more harmful drug than heroin".(2)
In many cases, drug abuse was heavy. On average, clients had abused heroin for nine years, although a quarter reported using opiates for at least 13 years. Twenty-two per cent used at least 1g of heroin daily. Roughly the same number of heroin abusers injected as smoked.(3)
Nineteen per cent of the residential group were abstinent from illicit opiates at enrolment, which increased to 47% after five years. In the community methadone group, the proportions were 6% and 35% respectively. Furthermore, 62% of the community group used opiates daily at enrolment, which declined to 20% after five years. The numbers of patients in the residential programme that used opiates daily and the proportion in both arms using nonprescription methadone also showed marked declines. Finally, crimes such as theft, burglary, shoplifting and drug selling that help fund addiction roughly halved.(3)
Nevertheless, methadone is not a panacea, as the following examples illustrate:

  • Around a third of patients leave methadone maintenance programmes during the first year. Another third of clients withdraw during the second and third years of treatment.(1)
  • Many clients continue to abuse drugs. During NTORS, a fifth of clients still used heroin daily. At the end of the study, 40% of clients used heroin at least once a week.
  • Mortality remains considerable. For example, approximately 6% of clients died during NTORS.(3)
  • The proportion of clients drinking above the recommended alcohol limit was 24% at intake and 25% at the end of the study.(3)
  • Methadone, like heroin, can induce dependency, tolerance and potentially fatal respiratory depression.

These problems highlight the pressing need for new approaches to the management of opiate dependency.

Buprenorphine: an alternative?
A combination of low abuse potential, good tolerability and relatively straightforward prescribing makes buprenorphine another option for treating addicts in the community.
Buprenorphine produces less euphoria, less sedation and milder withdrawal symptoms than heroin or methadone. As a result, it is a class C drug. In contrast, methadone is a class A drug. Buprenorphine's ease of use in primary care might, in turn, increase the number of addicts that can benefit from treatment.
Furthermore, buprenorphine produces a ceiling effect on respiratory depression. This makes buprenorphine safer in overdose than heroin or methadone, which produces increasing respiratory depression as the dose rises. Buprenorphine also blocks the effect of any additional opiates that the client subsequently takes.(4,5)
Buprenorphine is effective in both maintenance and withdrawal. For example, a recent Cochrane review reported that high-dose buprenorphine was superior to placebo at retaining patients in treatment and suppressing heroin use. High-dose buprenorphine suppressed heroin use more effectively than low-dose methadone. There seemed to be no statistically significant difference between high-dose methadone and high-dose buprenorphine at retaining patients in treatment. On the other hand, high-dose methadone was better at suppressing heroin use than high-dose buprenorphine.(6) It is important to remember, however, that buprenorphine has a more benign side-effect profile than high-dose methadone.
Emerging evidence suggests that buprenorphine may be more effective than methadone in opiate-dependent clients with concurrent depression.(7) Further studies are needed to confirm this observation, which could be clinically important. In NTORS, for example, 29% of patients reported suicidal thoughts in the three months before enrolment.(3)
Against this background, recent UK consensus guidelines suggest using buprenorphine for opioid-dependent clients who are taking, or can reduce their dose to, less than 30mg methadone daily.(4) The dose increases to a level that prevents withdrawal symptoms, although the maximum in the community is 32mg daily.(4) The guidelines suggest that buprenorphine might be especially valuable for clients who want to stop using opiates, avoid severe withdrawal from methadone or switch rapidly to naltrexone after detoxification.
Switching between opiates could precipitate acute withdrawal. As a result, clients should receive their first buprenorphine dose at least eight hours after they last took heroin. The liver takes methadone up, which it then releases slowly.(2) As a result, clients should allow between 24 and 36 hours after the last methadone dose. Ideally, patients should start buprenorphine when the first signs of mild-to-moderate withdrawal emerge.(4)
Nurses should make sure that clients understand buprenorphine's role and effects. In particular, nurses should counsel clients about the side-effects - restlessness, insomnia and diarrhoea - that may emerge during the first three days of treatment. They should reassure clients that such events usually subside rapidly.(4)
Nurses should also remember that both methadone and buprenorphine could interact with other central nervous system depressants, including benzodiazepines, antidepressants and alcohol. As a result, nurses need to advise clients to avoid CNS depressants while taking buprenorphine or methadone.

Conclusion
Opiate abuse imposes a heavy burden on society, addicts and their families. Methadone helps wean addicts off illicit opiates and offers the opportunity to develop a drug-free lifestyle. Nevertheless, methadone is not a panacea, and new approaches to management are needed. Randomised clinical studies show that buprenorphine aids maintenance and withdrawal. Combining psychological support, opioid replacement and symptomatic treatment can allow addicts to escape the prison of opiate addiction.

References

  1. Stimson GV, Metrebian N. Prescribing heroin: what is the evidence? 1st ed. York: Joseph Rowntree Foundation; 2003.
  2. Brust JCM. Neurological aspects of substance abuse. 2nd ed. Boston: Butterworth-Heinemann; 2004.
  3. Gossop M, et al. NTORS after five years: Changes in substance use, health and criminal behaviour in the five years after intake. London: Department of Health; 2001. Available from URL: http://www.dh.gov.uk
  4. RCGP. Guidance for the use of buprenorphine for the treatment of opioid dependence in primary care. Available from URL: http://www.rcgp.org.uk/drug/docsbuprenorphine.pdf
  5. Ling W. Research Clin For 2001;23:11-7.
  6. Mattick RP, et al. Cochrane Database Syst Rev 2004;CD002207.
  7. Gerra G, et al. Drug Alcohol Depend 2004;75:37-45.