Byrne AJ, Wodak A. Census of patients receiving methadone treatment in a general practice. Addiction Research 1996 3:4;341-9
CENSUS OF PATIENTS RECEIVING METHADONE TREATMENT IN A GENERAL PRACTICE.
ABSTRACT:
Objectives:
To describe the demographic characteristics, drug use and treatment outcomes of 121 patients currently receiving methadone treatment in an experienced inner-city general medical practice in Sydney, Australia.
Methods:
In a cross sectional survey of all patients receiving methadone treatment, self-reported data were collected by administered questionnaire. Results were corroborated with supervised urine tests, medical records and other documentary evidence wherever practicable.
Results:
Sixty-eight patients (56%) reported no heroin use in the previous six months. The mean duration opioid-free was 17 months. Morphine (heroin metabolite) was detected in 75 (7.4%) of 1009 random, supervised urine tests from 114 patients in a six month period. Employment rate increased substantially (28% vs. 56%). Patient's age, dose, duration in treatment, prison history and seroprevalence rates of HCV and HIV were found to be comparable with data from other reported experience.
Conclusion:
Outcomes from general practice based methadone treatment appear to be at least as satisfactory as from special clinics but offers the probable benefits of facilitating reintegration of patients into the general community and providing primary health care to this disadvantaged population.
INTRODUCTION
Illicit heroin use was uncommon in Australia before the Vietnam War. During the last three decades, heroin use has become recognised as a major social problem in Australia resulting in considerable adverse health, social and economic consequences. A conservative estimate of the economic cost of illicit drugs to Australia in 1988 was $1.4 billion (Collins and Lapsley, 1988). The use of illicit drugs in Australia was estimated to be responsible for 508 deaths, 17,954 premature years of life lost and 9,906 hospital separations by 1991 (Holman et al, 1988). Despite an increase in the use of psychostimulants (especially amphetamines) in Australia during the last decade, heroin is still generally recognised to be the most commonly injected illicit drug in Australia.
Methadone treatment for heroin dependence was introduced in 1964 in New York and first used in Australia in 1969. Methadone was the only treatment for drug users specifically endorsed at the Special Premier's Conference in Canberra in 1985 (Commonwealth Department of Health 1985). Studies of methadone treatment have shown it to be safe, cost-effective and to result in a reduction of illicit drug use, criminality and HIV infection (Ward et al. 1992; Novick et al.1990; Novick et al. 1993).
In most Australian states, demand for methadone treatment exceeds availability even though the number of patients undergoing treatment has been increasing by 10-15% per annum and exceeded 15,000 patients in 1995. The administration of methadone treatment in Australia varies considerably from state to state. In New South Wales and Victoria, the two most populous states, general practitioners provide most methadone treatment services while specialist methadone clinics provide the majority of services in Queensland, South Australia and Western Australian.
In 1986, as part of an initiative to rapidly increase the availability of methadone treatment in New South Wales (population 6.0 million), a number of general practitioners in Sydney agreed to prescribe methadone for patients with heroin dependence. The state now has approximately 200 medical practitioners approved to prescribe methadone for the management of heroin dependence of whom about three quarters are general practitioners. A substantial number of all patients receiving methadone treatment in New South Wales attend large clinics which are often staffed by one or more general practitioners.
Most research in methadone treatment has been conducted in specialist clinics. There are few reports of the use of methadone treatment in general practice. Some have reported small numbers of patients followed for short periods, while others describe stable patients on methadone who were referred from specialist clinics to general practices for continuing care (Greenwood 1990, Robinson and Thornton 1994, Cohen et al. 1992, Land and Zenker 1994).
General practice based methadone treatment services are growing rapidly in Australia and are now being introduced in states that previously depended on specialist clinics. This paper describes the practice methods, patient profile and treatment outcomes of a substantial number of patients receiving methadone treatment from an inner-city general practice in Sydney with seven years experience of this treatment.
METHODS
Recruitment of Patients:
Patients who lived or worked within the area and were referred from other medical practitioners and local hospitals were assessed at presentation without appointment. Pregnant injecting drug users were referred to a nearby specialist unit for management. Patients were encouraged to pursue other forms of treatment if they were less than 18 years old, using non-opioid drugs, injecting heroin infrequently or had a short history of injecting heroin. The majority of patients accepted for methadone treatment had unsatisfactory results from a range of previous treatments. At the initial assessment, other treatment options were discussed including detoxification, Narcotics Anonymous and residential rehabilitation programs.
Practice Setting:
Patients with drug and alcohol problems who attended the practice were treated in the same setting and on the same conditions as other general patients. The time devoted to patients with drug and alcohol problems increased from less than 10% in 1986 to approximately 50% at the time of the study in 1993. The practice was staffed by one full-time general practitioner (AB), who also managed all patients receiving methadone treatment, one part-time general practitioner, one part-time post-graduate trainee physician and two experienced registered nurses. In the six months prior to the study two patients were referred to a nearby community centre providing psychiatrist, psychologist and social work services. Typically two patients commence methadone with two departing the treatment each week. The practice aims to provide a non-judgemental, ethical and comprehensive treatment service using principles originally advocated by Dole (1965). Only under exceptional circumstances are patients discharged. The practice is located in an inner suburb with a high proportion of disadvantaged people including unemployed, single parents and Australian Aboriginal people.
Assessment and urine testing:
Patients were only considered for methadone treatment after showing proof of identity and satisfying National Methadone Guidelines criteria for treatment including a characteristic history of compulsive opioid use. A general physical examination was performed with special attention to venipuncture sites, pupil size, mental state and abdominal palpation. A urine drug screen was ordered on each patient, and blood examination recommended if recent results were not available. Patients requesting methadone who lived or worked in the area and satisfied medical indications for methadone treatment were generally accepted, with medication usually commencing on the same day. Those living in other localities or with other needs were generally found alternative treatment promptly.
All urine specimens were collected under supervision and subjected to 'EMIT' screening for benzodiazepines, cannabis, opioids, sympathomimetic amines, cocaine, barbiturates, propoxyphene and methadone. If the EMIT test was positive, confirmation was performed with the more specific but less sensitive 'Toxilab B' chromatography test. Collection of urine specimens was supervised using vertical closed-circuit video monitor. Specimens were collected weekly on new patients and less often as treatment progressed.
Commencement of treatment:
The usual starting dose of methadone was 30-40 mg per day. This was gradually increased while signs of opioid withdrawal were present and illicit drug use continued. Where increments of over 10mg were required for withdrawals, patients attended twice daily to reduce the known risk of overdose in the initial period. Patients considered for doses exceeding 100mg were assessed three hours after medication and plasma levels ordered. New patients were seen three times in the first week. Subsequent weekly consultations (lasting from 10 to 30 minutes) occurred until patients were considered stable. Consultations then became less frequent depending upon progress and the presence of other medical conditions. While the details of treatment are beyond the scope of this article, goals and priorities were reviewed regularly with each patient. The nature of the dependence, guilt, denial and self medication were also addressed in the consultations. Stable patients were permitted a degree of control over methadone doses, subject to negotiation with the methadone prescriber.
Nearly all the study patients used the primary care facilities of the practice at least once during a six month period. Approximately half of the patients stated that they did not have a family doctor and used the practice for all their primary care needs.
Dosing Arrangements
Methadone syrup was dispensed daily under supervision. Following an initial stabilisation period, those who curtailed heroin use were permitted three times weekly attendance and provided with take-home doses for the remaining four days of the week. A number of long term stable patients on low doses received methadone twice or even once weekly. Security, storage and facilities for supervised urine testing were installed at the practice. Approximately three quarters of the study patients received methadone at the practice site which opens at 8am six days per week. The remaining patients attended pharmacies or clinics near home or work, returning to the practice for consultations and prescriptions. Every effort was made to facilitate employment and travel opportunities by flexible dosing arrangements.
There have been only minor problems with bad language or behaviour. The police have been called less than once per year on average, in most cases for patients refusing to leave, claiming that they were not getting what they wanted.
Although much of the local residential and commercial community is aware of the nature of the practice, there have been no specific complaints received. Many local property owners, business people and workers have attended the practice over the years, some for drug and alcohol related problems.
Collection of Data
A questionnaire covering drug use, social and medical parameters was administered in interviews lasting approximately 20 minutes. All interviews were conducted in November 1993. Wherever possible, self-report data were checked with urine tests and practice medical records. Informed consent was obtained before entry to the study.
RESULTS
Demographic characteristics:
One hundred and twenty-one patients were prescribed methadone at the time of the questionnaire. The mean age was 32.8 years (standard deviation: ± 6.6 years). The patients were predominantly male (82%). Average age of leaving school was 15.9 ± 2.0 years. Sixty-five patients (54%) had either a spouse or first order relative with opioid dependency. Forty-seven patients (39%) had been incarcerated for over one month with cumulative period of imprisonment averaging 26 months. The mean distance between the patients' residence and the medical practice was 4.1 km (excluding seven patients who had moved to rural areas).
The mean age of first heroin use was 20.1 years (± 4.5 years) and mean total duration of heroin use was 66 months. Four patients stated that they had usually consumed opioids by routes other than injection. One hundred and six patients (88%) reported that they were current smokers and 52 (43%) currently consumed alcohol.
Methadone treatment:
The mean daily methadone dose was 68 mg (± 48 mg, range 2.5-300 mg). The mean duration of current treatment was 28 months (± 24 months) with mean cumulative total duration in methadone treatment being 42 months (± 33 months). 51 patients (42%) had not previously received methadone treatment. Treatment duration was comparable with contemporary State experience (see Table 1).
Outcomes:
The mean duration since last reported heroin use was 17 months (± 25 months). The mean reported number of days of heroin use in the month preceding interview was 0.7 (± 1.5). Sixty-eight patients (56%) reported no intravenous drug use in the previous six months. The remaining 53 (44%) reported a total number of 251 injecting episodes whilst on treatment. The drugs reported were heroin (45 patients), amphetamine (4), methadone (2) and mixed drugs (2). Of 97 patients on treatment for more than six months, 65 (67%) reported no heroin use during the six months.
Thirty-eight patients (31%) reported having ever had a problem with alcohol while 12 (10%) reported a current drinking problem. Thirty-five patients (29%) reported ever experiencing problems with drugs other than opioids, while 21 (17%) reported current problems with a range of preparations which included benzodiazepines (9 patients), cannabis (4), cocaine (3), amphetamine (3) and multiple drugs (2). ('Problems' were defined by adverse effects upon health, finances, the family, or work.)
At the time of interview, 67 patients (55%) were employed (41% full time, 14% part time) compared to 34 (28%) who had any regular work before treatment. Nineteen patients (16%) were not currently employed due to sickness or sole parent status.
Five patients (4%) reported sharing injecting equipment during the previous six months. All instances occurred with regular sexual partners.
In the six months preceding interview, 1009 random, supervised urine tests were performed on 114 patients (mean 9 tests per patient, range 1 - 19) with cannabis being the most frequently detected drug (33% of tests) followed by opiates (20%) benzodiazepines (12%), morphine (7.4%), amphetamine (3.7%) and cocaine (3.2%). Thirty patients (25%) had one or more tests positive for morphine in the six month period, including 13 positives from the 24 patients commencing treatment during that period.
Blood testing was available for 120 (99%). Abnormal liver function tests (AST, ALT or gGT) were found in 67/120 (56%), with at least one result double the upper the limit of normal in 34 patients (28%). HIV testing was positive in 2/120 (1.7%). Of 92 patients tested for HCV, 88 (96%) were positive. The mean trough plasma methadone level for 36 patients receiving a mean dose of 72mg was 0.21mg/l (± 0.17mg/l) (therapeutic range 0.10 - 1.00 mg/l). Mean peak levels for 4 patients on high dose (206mg ± 80mg) were 0.75mg/l (± 0.17 mg/l).
DISCUSSION:
This study represents an audit of a large number of patients receiving methadone treatment from a general practice with considerable experience with this treatment. Although the lack of a formal research protocol might reduce the confidence of some findings, the fact that the study conditions were naturalistic and not altered to suit a research design, suggests that the findings are likely to be generalisable to other general practice based methadone treatment programs. The study was prospective with all interviews conducted by one researcher (AB). All practice patients on methadone treatment at that time participated in the study.
Data reported to the prescriber may have been subject to desirability bias. To minimise this, all self-report data accepted for this study were corroborated by reference to medical records which recorded regular examinations of venipuncture sites and urine test results. Reported employment was only accepted with documentary evidence.
Urine test results in this study probably underestimate the benefits of treatment as testing was performed more frequently on unstable and new patients. Urine testing during the study period was not carried out at all on five stable patients who showed evidence of considerable social rehabilitation, including numerous previous urine tests with no evidence of illicit drug use.
Morphine, the major metabolite of heroin, is detectable for up to 72 hours following heroin use. The EMIT test for opiates remains positive for up to six days, but is also positive for other opioids such as codeine. As the mean duration between urine tests in this study was 19 days, the results tend to underestimate the extent of heroin use. More patients reported heroin use than were detected by urine testing (53 vs. 30).
The finding that 7.4% of all urine tests in this study were positive for morphine is much lower than the 22.9% reported in a large study of 346 methadone patients (Lewis and Chesher 1990). The finding of 17 months for the mean interval since last heroin use would appear to be satisfactory, in patients who had been on treatment for an average of 28 months.
Studies have shown that higher methadone doses and some patient control over the levels are both associated with better outcomes (Hargreaves 1983, Goldstein et al. 1975, Havassy and Hargreaves 1979). A substantial proportion of patients receiving 80mg of methadone had low plasma methadone levels (Tennant 1987) and significantly improved outcomes were demonstrated when the dose was increased to 100mg. Despite such compelling evidence, many treatment services still use dose ceilings under 100mg, as well as encouraging premature dose reductions (D'Aunno and Vaughan 1992). These established treatment principles were followed in the study practice. Nine patients (8%) received daily doses in excess of 150mg. Four patients (3%) had first received methadone more than ten years previously.
The preponderance of males (82%) in this study may be partly due to the practice of referring pregnant women to a specialist service in a nearby obstetric hospital. In addition, the publicly funded drug and alcohol unit for this locality had a policy of not accepting males, giving preference to women in pregnancy or with young children. Women in such treatment also qualified for free dispensing, where patients in the study practice paid on average US$3 per day to the various dispensing locations used. A review of methadone programs in other parts of Sydney (Caplehorn 1992) found the proportion of males in treatment ranged from 61% to 73%.
The favourable outcomes of patients in this study could have resulted from patient selection or the provision of effective treatment. There appears to be no evidence that patients in this study were selected for good outcomes. Duration in treatment closely follows state averages for each published interval (see Table 1). In several other important aspects the group proved comparable with the results available for all NSW patients, as well as with a number of other published studies (see Table 2). Current age, dose, age of first heroin, education history, retention in treatment, previous methadone treatment, incarceration rates, HCV and HIV status were all compared with other published figures. Only the age of first heroin use showed a significant difference (of one year). While not all contemporary, the findings are still believed to be applicable. Even if selection played a rôle, the study still suggests that good outcomes can be achieved in a medical practice setting with such patients.
In a large study of six methadone programs in the United States, treatment characteristics were found to have a far greater influence on outcome than pre-treatment findings (Ball and Ross, 1991) suggesting that patient selection is unlikely to contribute substantially to observed outcome.
CONCLUSIONS:
These results suggest that good or even excellent outcomes can be achieved with methadone treatment in a general practice setting. General practice based methadone treatment offers a number of advantages compared to specialist clinics. It allows the development of close doctor-patient relationships which are more difficult to achieve in the more impersonal settings of a clinic. Specialist clinics with large case loads are increasingly resented by local residents. Difficulties have been experienced in establishing new clinics as well as maintaining existing clinics in some jurisdictions. Providing methadone treatment in general practice offers an opportunity to facilitate the reintegration of illicit drug users back into the community while also providing primary health care to a population with substantial medical problems. In addition, primary health care can be offered to other members of the drug user's family, which may not be feasible in the clinic setting.
The experience of the study practice has been very positive. Most patients have presented with heroin dependence accompanied by other major social and medical problems. While demanding at times, it has been gratifying to be involved with the rehabilitation of these patients. After seven years, almost 100 patients have completed methadone treatment and are known to have become drug free.
Methadone treatment has now been accepted for implementation in a number Western European countries previously hostile to this treatment modality. This reassessment has come about in the light of increasing evidence of benefit across a range of outcomes, especially the ability of methadone treatment to reduce the spread of HIV infection. Most research and clinical experience with methadone in Australia and overseas has been gained from clinic based services. The results of this study should be regarded as tentative as there was no control group or random assignment. Nevertheless, the study suggests that general practice based methadone treatment may be at least as effective as clinics. Further research is required to compare the results of methadone treatment from specialist clinics with general practice based methadone treatment.
TABLE 1: Duration of treatment by intervals. All figures percentages.
DURATION GENERAL PRACTICE TOTAL PATIENTS (NSW) *
(n = 121) (n = 7495)
0-6 months 20.6 20.5
6-12 months 17.4 14.8
1-3 years 30.6 34.0
3-5 years 19.8 16.5
> 5 years 11.7 14.2
* Source - Commonwealth Tables, NSW Methadone Program.
Comparison of two groups: ² = 2.31, degree of freedom = 4, p = 0.7. Not significant.
TABLE 2: Comparison of selected findings with other published results.
PARAMETER GENERAL PRACTICE OTHER STUDIES
(n = 121 unless stated)
Current age 32.8 ± 6.6 32.75 (a) ns
Age finished education 15.9 ± 2.0 16.1 ± 2.4 (c) ns
Age first heroin use 20.1 ± 4.5 19.0 ± 4.1 (c) p <> 1 month 47 (39%) 32% (c) ns
Time in prison (months) 26 ± 33 (n = 50) 23 ± 25 (n = 146) (c) ns
HCV positive 89/93 (96%) 94.3% (d) ns
HIV positive (males only) 2/99 (2.0%) 1.2% (e) ns
(a) Commonwealth Tables. New South Wales Methadone Program, 1993. (n = 7506).
(b) Proportion in contemporary entries to treatment in NSW (n = 1008) (Commonwealth Tables). Groups not statistically comparable: new vs current patients.
(c) Caplehorn, 1992 (n = 457).
(d) Gaughwin et al., 1994 (n = 87).
(e) Bell et al., 1990. n = 483 (males).
ns - not significant (p > 0.05)
F I N E
References:
Ball J, Ross A: The Effectiveness of Methadone Maintenance Treatment. p242
Springer-Verlag, New York 1986.
Bell J, Fernandes D, Batey R. Heroin users seeking methadone treatment. Medical
Journal of Australia 1990;152:361-4.
Caplehorn JRM. A comparison of private and public methadone maintenance
patients. Drug and Alcohol Review 1992;11:43-49.
Cohen J, Schamroth A, Nazareth I, Johnson M, Graham S, Thomson D. Problem drug use in a central London general practice. (1992) British Medical Journal;306 (6835)
Collins DJ, Lapsley HM. (1991) Estimating the economic costs of Drug Abuse in
Australia, National Campaign Against Drug Abuse. Monograph Series No. 15.
Australian Government Publishing Service, Canberra.
Commonwealth Department of Health (1985). National Campaign Against Drug
Abuse; Campaign documents.Australian Government Publishing Service,Canberra.
Commonwealth Tables, New South Wales Methadone Program, (1991-1993) Drug
and Alcohol Directorate, New South Wales Health Department.
D'Aunno T, Vaughan TE. Variations in methadone treatment practices; results from a
national study. Journal of the American Medical Association. 1992;267:253-8.
Dole VP, Nyswander ME. A medical treatment for diacetylmorphine (heroin)
addiction. Journal of the American Medical Association. 1965;193: 80-84.
Gaughwin M, Dodding J, Ali R. Hepatitis C and the history of injectomg drug use in
South Australia [letter] Medical Journal of Australia 1994;161:286-287.
Goldstein A, Hansteen RW, Horns WH. Control of methadone dosage by patients:
Journal of the American Medical Association. 234:734-737.
Greenwood J. Creating a new drug service in Edinburgh. British Medical Journal
990;300:587-9.
Hargreaves WA. Methadone dosage and duration for maintenance treatment. In
Cooper JR, Altman F, Brown BS Szechowicz D, (Eds) Research on the Treatment
of Narcotic Addiction: State of the Art. Maryland: NIDA, U.S. Department of
Health and Human Sciences, 1
Havassy B, Hargreaves WA. Self-regulation of dose in methadone maintenance with
contingent privileges. Addictive Behaviors, 1979; 4:31-38.
Holman CDJ, Armstrong BK, Arias LN, Martin CA, Hatton WM, Hayward LD,
Salmon MA, Shean RE, Waddell VP. The quantification of drug caused morbidity
and mortality in Australia. Commonwealth Department of Community Service and
Health, Canberra 1988. Ministerial Council on Drug Strategy. National Methadone
Guidelines. Published by the Australian Government Publishing Service, Canberra.
Land P, Zenker C. Methadone Treatment of Drug Addicts in Bremen Research
Results. Sucht 1994;4: 253-265
Novick DM, Joseph H, Croxson TS, Salsitz EA, Wang G, Richman BL, Poretsky L,
Keefe JB, Whimbey E. (1990) Absence of antibody to human immunodeficiency
virus in long-term, socially rehabilitated methadone maintenance patients.
Archives of Internal Medicine;150:15-25.
Novick DM, Richman BL, Friedman JM, Friedman JE, Wilson JP, Townley A, Kreek
MJ. The medical status of methadone maintenance patients in treatment for 11-18
years. Drug and Alcohol Dependence, 33 1993:235-245.
Robinson GM, Thornton N. Methadone in general practice. New Zealand Medical
Journal; 1994:Jan 26[Letter].
Tennant FS. Inadequate Plasma Concentrations in Some High-Dose Methadone
Maintenance Patients. American Journal of Psychiatry 1987; 144: 1349-1350.
Ward J, Mattick RP, Hall W. Key Issues In Methadone Maintenance Treatment,
NSW University Press Ltd, 1992;272-273.
Wilson P, Watson R, Ralston GE. Methadone maintenance in general practice:
patients, workload, and outcomes. British Medical Journal 1994;309:6
41-4.
