In the UK, injectable opiates have been used longer than in any other country as a treatment for heroin misuse (Reference Strang and GossopStrang & Gossop, 1994). Also, while others have started using injectable diamorphine with promising results (Reference Perneger, Giner and Del RioPerneger et al, 1998; Reference Van Den Brink, Hendricks and BlankenVan Den Brink et al, 2002), the UK remains almost unique in continuing to provide injectable methadone. In 1995 this was the chief injectable used, comprising 90% of injectable prescriptions in England and Wales (Reference Strang, Sheridan and BarberStrang et al, 1996).

In the studies above carried out in mainland Europe, injectable medications have been administered under high levels of supervision in dedicated injection rooms. The Randomised Injecting Opioid Treatment Trial (RIOTT) study under way in the UK (Reference Lintzeris, Strang and MetrebianLintzeris et al, 2006) has recreated these conditions to a large extent and it will add invaluable information to the burgeoning scientific literature on injectable medications. There is, however, still a need to do more to examine the current practice in the UK as it has evolved over 30 years within the context of less close monitoring arrangements.

Reflecting on these arrangements, in 2003 the National Treatment Agency published a report with guidelines on the use of injectable medications (National Treatment Agency, 2003). It stated that ‘injectable maintenance treatment is most appropriate for addicts who have not responded to oral maintenance treatment’. It also listed eligibility criteria and a number of cautions and precautions. However, it contained little information on a number of issues which are of practical concern to clinicians in the field, for example, intramuscular or subcutaneous administration and appropriate responses to individuals who persist in using their medications in a potentially harmful manner.

Thus, although it provides a template for good practice, some aspects of the report appear more aspirational than achievable. A survey of 104 people receiving injectable opiates in the north-east of England was carried out in 2000 (Reference Sell and ZadorSell & Zador, 2004). Among this sample, 93% used their medication intravenously and more than half injected it into the femoral vein (groin); injectable diamorphine was preferable to injectable methadone. Though the reasons for this preference were not explored in detail, there was a clearly stated desire among those on methadone to be switched to diamorphine. The survey did not study the previous experience of individuals who had had both medications, but it highlighted the fact that very few of them appeared motivated to stop injecting or to detoxify, and for many the immediate goal in treatment was increasing the dose.

We felt it was important to audit the safety and effectiveness of local practices to measure them against the national standards as outlined in the National Treatment Agency report (2003), to understand how clients use injectable medications when unsupervised (including whether they prefer to apply them intravenously or intramuscularly) and to establish a baseline measure of complication rates with both medications. We also wanted to report on the nature of clinical practice as it has evolved locally. We hoped that this would help guide future practice.

Method

Cornwall is an impoverished rural/maritime county in the far south west of England, with average incomes among the lowest in the European Union (The Guardian, 2005).

Around 10% of individuals receive a substitute prescription from the specialist prescribing service (community drug and alcohol team) in the form of an injectable opiate, either methadone or diamorphine. Injectable methadone is nearly always offered before injectable diamorphine is considered, and the patient is encouraged to inject their medication intramuscularly where possible, especially diamorphine. This local policy has been adopted partly because many individuals on injectable medications do not have accessible veins and partly because there should be a lesser risk of overdose.

While excessive alcohol intake is discouraged in patients receiving an injectable prescription, this has only very rarely been used as a reason to stop or reduce the medication.

Patients were approached by a dedicated researcher in clinics predominantly in the mid and west of Cornwall. She sought to recruit individuals for interview during a fixed period in October and November 2006.

Out of 66 individuals in receipt of an injectable script, 51 were interviewed. One further refused to take part, and another aborted the interview, which gave us a 96% response. The remaining 13 individuals were not interviewed because of relative inaccessibility (most lived in the small dispersed communities in North Cornwall). Rather than being asked about their current prescription, participants, many of whom had used both diamorphine and methadone, were asked about their experience with both medications.

Results

Discussion

Prescribing injectable medications has been almost unique to British psychiatry and so it is important to document existing practices. This was the first survey of injectable prescribing in a rural part of the UK.

Our data support the view that injectable opiods have been used by local clinicians only when other treatments have failed. The eligibility criteria employed locally are therefore in line with National Treatment Agency's recommendations (2003).

Regarding patient's own experiences, problems were twice as likely to be reported using injectable methadone, regardless of whether it was injected intramuscularly or intravenously. Injectable methadone can be painful to administer, which in our view is one of the main reasons why most patients consider it inferior to diamorphine and why they may be more likely to inject it into larger, more central, veins.

The complication rate for those that injected both drugs intramuscularly appeared higher than that for medications injected intravenously and it is unclear whether or not this is caused by poor injection technique. Failure to clean injection sites was common and yet this would probably not explain the higher complication rate for intramuscular use as compared with intravenous use, as it would seem unlikely that a person would clean their skin for one mode of administration and not for the other. The risk of overdose should be less with intramuscular administration, but this type of administration should be recommended cautiously – and not routinely – as part of an overall harm-reduction strategy. Intravenous use may be preferable in some instances.

More than 15% of both groups were frequently injecting their medication into their groins and several admitted to injecting into their neck veins. This usually occurs when more peripheral veins are not accessible, another feature of the usage of injectable opioids (Reference Sell and ZadorSell & Zador, 2004). It is under these circumstances that it would seem preferable to recommend to the patient to apply their medication intramuscularly, the strategy that has been used locally. However, this is difficult to monitor and verify without witnessing every individual administration.

The rate of daily on-top alcohol misuse was quite high in both groups. This was more of a concern in the methadone group who were also more likely than the diamorphine group to still be misusing heroin. Although many individuals in the diamorphine group were drinking alcohol regularly, none of them were continuing to misuse street heroin. The National Treatment Agency guidelines suggest that ongoing alcohol misuse, rather than contraindicating an injectable script, is a reason to ‘exercise caution’. It does seem reasonable that where a diamorphine treatment has been successful at stopping street heroin misuse and increasing harm reduction gains, it should not necessarily be withdrawn merely because the individual is misusing alcohol. However, alcohol-related pathology and health costs should not be underestimated in this group.

After over 5 years of prescribing injectable diamorphine to around 50 patients and a longer period of prescribing to a smaller group, none of the patients died due to overdose, though a few died following physical illness (e.g. liver failure). Overdose therefore appears to be a rare event and we would question the need for supervised administration as it is being adopted elsewhere.

In rural areas, such as Cornwall, providing supervised administration facilities (injecting rooms) is likely to prove prohibitively expensive, and having other safeguards in place that limit leakage of medications onto the black market may have to be sufficient. This could include an ampoule return scheme similar to the one we have developed, where pharmacists are paid to count returned ampoules before dispensing the next prescription. More guidance to commissioners is needed in this area.

In Cornwall we have also initiated a ‘diamorphine panel’, a special review clinic for patients on diamorphine attended by the prescribing consultants, the service manager and the service user coordinator. This was initiated when, for cost purposes, rationing of diamorphine was introduced in Cornwall over a year ago. The panel reviews individuals once a year, sets treatment goals and prescribes diamorphine to those most in clinical need.

Cost is still a big issue. Diamorphine continues to be far more expensive in the UK than Europe and supplies remain somewhat precarious despite the notable failure of supply that hit the UK in 2004/5 (Reference White, Cox and CharnaudWhite et al, 2005). These issues of paramount importance are ones that only the government can address, relating as they do to the legislative controls around opium refining and manufacture. Establishing the cost-effectiveness of injectable prescribing in the UK will hinge on this chronically unresolved issue and so for the foreseeable future guidance to clinicians and commissioners will remain unclear.

Declaration of interest

None.