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A survey of supervised consumption of methadone in England

Key Words: methadone, opiate misuse, supervised consumption, drug related deaths

Abstract

Methadone is the most widely used drug treatment in opiate dependence in the United Kingdom. Deaths from black-market methadone remain common. Regulations suggest that methadone should be supervised by a Pharmacist for at least 3-6 months. Over 1000 community pharmacies were contact in 18 different areas in England. On average one-third of the 4300 patients on methadone were supervised although there was significant variation between areas (range from 9% to 62%). Six of the 18 areas had rates of supervised methadone consumption less than 30%. This suggests that the recommendations regarding supervised consumption of methadone are impractical or widely ignored in England.

Introduction

Methadone is an opioid drug that is the most widely used drug treatment for opiate dependence (National Consensus Development Panel, 1998). Methadone treatment is undoubtedly effective although there remains controversy over the relative benefits of maintenance (long-term) or detoxification treatment (Ward et al, 1999). In England, unlike many countries, methadone has been commonly dispended to opiate addicts to take away and consume at home. Methadone has a low therapeutic index – deaths have been reported from doses of 40 mg in opiate naïve individuals (Ghodse et al, 2005; Luty 2005). Moreover the British press has widely publicised two cases of children under 3 years old dying from ingestion of their parent’s methadone (Satchell, 2003; Gillan, 2006).

Many authorities recommend methadone maintenance doses of between 60 and 120 mg although all responsible guidelines would recommend starting doses below 40 mg (Department of Health, 1999). Methadone has a similar capacity to cause respiratory depression than heroin (Bickel & Amass, 1995; Johnson et al 2000). However black-market methadone has little euphoric effect and, consequently it is relatively inexpensive - users often report that 200 mg of methadone can be bought for £10-£20 (US $15-30) on the black market (Seivewright, 2000). This is at a time when clients typically spend £40 (US $60) per day on illicit heroin (Luty et al 2006). In the late 1990s there were consistently more death from methadone overdose than from overdose of illicit heroin (Royal College of Psychiatrists, 2000). Just over half of these deaths were due to diverted methadone—that is, methadone that had been sold to the victim on the black market. Consequently the UK Department of Health and the Home Office both produced guidelines that recommend that methadone consumption should be supervised directly by a Pharmacist (or other health professional) for the first 3-6 months of treatment (Council on the Misuse of Drugs, 2000; Department of Health, 1999). This has lead to a significant reduction in the number of deaths related to methadone (Ghodse et al, 2005). However the annual reports on drug related deaths in the UK indicates there are currently around 150-200 methadone related deaths per annum – half of which are due to diverted methadone – that is methadone that is bought on the black market (Ghodse et al, 2005.

We chose to perform a survey of Community Pharmacies at several sites throughout the UK to survey the relative proportion of patients undergoing supervised methadone consumption.

Method

Community Pharmacies were identified using the British Telecom telephone directories for 18 randomly selected districts in England. Pharmacists were contacted by telephone in each area until either results were available for 100 Pharmacies or data was available for at least 30 subjects on supervised methadone. Pharmacists were asked how many patients received methadone from them and how many had regular supervised consumption of methadone. No patient identifiable information was collected.

Results

Results were obtained from 1005 Pharmacies who dispensed methadone in the 18 English districts. In total 4307 patients received methadone of whom 1397 were in receipt of supervised methadone - 33.5% (standard deviation=14.3%) (inter-quartile range intervals 25%-40%). There was significant variation in the proportion receiving supervised methadone with a range from 9% to 62%. The three areas with the lowest rate of supervised consumption had rates of 9%, 11% and 13% while three areas had rates of 25%. 6 of the 18 areas had rates of supervised methadone consumption less than 30%.

Discussion

There remains some confusion amongst the various recommendations. The Home Office guidelines recommend supervision for “a minimum of six months” whereas the Department of Health recommend “at least 3 months” (Advisory Council on the Misuse of Drugs, 2000; Department of Health, 1999). The guidelines do make exceptions according to individual circumstances - usually interpreted as patients who are working and therefore unable to attend a Pharmacist during business hours. It would be helpful if these guidelines were consistent and there was a specific statement as to which patients should be excepted from supervised consumption. Moreover these guidelines suggest that supervised consumption be continued for patients on higher doses of methadone but do not indicate what constitutes “higher doses”. This would presumably be daily doses exceeding 50 mg (doses that can be fatal in opiate naïve individuals) but this is open to interpretation. We note that the average dose of methadone used in the UK is 40-50 mg and many authors regard this as inadequate (Joseph & Moselhy, 2005).

The National Treatment Agency for Substance Misuse in England has reported that in 2004/5 there were 160 000 people in treatment in the England and Wales for illicit drug problems (www.nta.nhs.uk). Around 80% of these patients had opiate problems many of whom were presumably eligible for substitute prescribing. There were 98 000 new treatment episodes in 2004/5. This would suggest that approximately 60% of people receiving substitute prescribing were new to treatment every year. The UK Home Office recommend that methadone is supervised for “a minimum of 6 months” (Home Office 2000). Supervised consumption is also recommended in patients who are receiving higher doses of methadone or those with other risk factors for drug-related deaths such as concomitant use of illicit drugs, prescribed benzodiazepines and alcohol misuse. Many districts that were surveyed had low rates of supervised consumption (6 out of 18 areas had rates of supervised methadone consumption less than 30%). It is clear that recommendations regarding supervised consumption of methadone are either impractical or widely ignored. We have recently contacted 120 community drug teams in England and Wales to ask what proportion of new patients on methadone undergo supervised consumption. We found that 22% of teams reported that methadone was supervised in fewer than half of new patients starting a prescription (Luty et al 2005). This proportion is likely to be much higher in people who remain on methadone in the long term. This study also showed that users have significant opposition to the restrictions imposed by supervised consumption of methadone. Both these factors are likely to explain the continued widespread dispensing of methadone for clients to take away despite the potential guidelines to the contrary.

References

Advisory Council on the Misuse of Drugs, (2000). Home Office Report: Reducing Drug Related Deaths. London: The Stationery Office.

Barnett, P.G., Rodgers, J.H. & Bloch, D.A. (2001) A meta-analysis comparing buprenorphine to methadone for treatment of opiate dependence. Addiction, 96, 683-690.

Bickel WK & Amass L (1995). Buprenorphine treatment of opioid dependence: a review. Experimental and Clinical Psychopharmacology 3: 447-489.

Department of Health (1999) Drug Misuse and Dependence: Guidelines for clinical Management. London: The Stationery Office.

de Wet C, Reed LJ & Bearn J (2005). The rise of buprenorphine in England. Addiction 100: 495-499.

Ghodse H, Corkery J, Schizfano F, Oyefeso A, Bannister D & Annan J (2005). Drug-related deaths in the UK. London: International Centre for Drug Policy Report 15, St George’s Hospital Medical School.

Gillan A (2006). Boy, 2, died after taking parents’ methadone. The Guardian: 6 March.

Johnson RE, Chutupe MA, Strain EC, Walsh SL, Sitizer ML & Bigelow GE (2000). A comparison of levomethadyl acetate, buprenorphine and methadone for opioid dependence. New England Journal of Medicine 343: 1290-1297.

Joseph, R & Moselhy HF (2005). A national survey of methadone prescribing for maintenance treatment. Psychiatric Bulletin 29: 459 - 461.

Luty J, O’Gara C & Sessay M (2005) Is methadone too dangerous for opiate addiction? British Medical Journal 331: 1352 - 1353.

Luty J, Perry V, Umoh O & Gormer D (2006). A short self-report outcome measure (MAP-SC) for opiate addiction treatment. Psychiatric Bulletin 31: 28-30

National Consensus Development Panel (1998). Effective medical treatment of opiate addiction. Journal of the American Medical Association, 280, 1936-1943.

Royal College of Psychiatrists (2000) Drugs: dilemma and choices. Pp 161. London: Gaskel.

Satchell C (2003). Methadone mum: Son’s death ’not my fault’. Manchester Evening News: 4 January

Seivewright,N. (2000) Community treatment of drug misuse: more than methadone. Cambridge University Press

Ward J, Hall W & Mattick R.P. (1999). Role of maintenance treatment in opioid dependence. Lancet 353: 221-226.

Authors

Dr Jason Luty* MB ChB PhD MIBiol Cbiol MRCPsych
Consultant in Addictions Psychiatry South Essex Partnership NHS Trust
Honorary Consultant Cambridge and Peterborough Mental Health NHS Trust
Community Drug and Alcohol Service
The Taylor Centre
Queensway House
Southend on Sea
Essex SS4 1RB

Dr Shoba Puttaswamaiah MB BS
Senior House Officer in Psychiatry
South Essex Partnership NHS Trust
Runwell Hospital
Runwell Chase
Wickford
Essex

Dr Jitendra Reddy Anapreddy MB BS
Senior House Officer in Psychiatry
South Essex Partnership NHS Trust
Runwell Hospital
Runwell Chase
Wickford
Essex

Dr Arghya Sarkel- Specialist Registrar in Psychiatry
The Taylor Centre
Queensway House
Essex Street
Southend on Sea
Essex SS4 1RB

First Published November 2007

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