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Heroin Assisted Treatment for Opiate Addicts – The Swiss Experience

 Ambros Uchtenhagen


The heroin epidemic started in Switzerland in the early seventies. A rapid increase led to an estimated number of 30‘000-40'000 addicts, ca. 0.5-0.8% of the total population (Estermann 1996). This elevated prevalence is in line with a high addiction liability in our population also for alcohol, tobacco and prescription drugs (Uchtenhagen 1991).  

Since the start of the epidemic, the characteristics of users have changed considerably. At first, drug use in general was associated with a strong movement of youth unrest and opposition to established societal norms and institutions. In the course of a learning process regarding drugs and the risks of drug use, the majority of young people adapted their behaviour to the perceived risks. Heroin got the image of a high-risk drug, in contrast to cannabis. However, the less educated, coming from multi-problem families, meeting more difficulties in the transition to a successful and satisfactory life as adults, became more prominent among heroin users (e.g. origin from a broken home was ten times elevated in comparison to the average). Finally, during the eighties, the prevalence of psychiatric morbidity among heroin users (dual diagnosis) increased.  

This development indicated a shift in motivation, from experimental and subcultural use to what is termed self-medication use (Khantzian 1985). In this perspective, heroin is used in order to alleviate from unpleasant sensations, fears and memories.



The therapeutic response to the drug epidemic was at first initiated by NGO’s, setting up Therapeutic Communities of the Phoenix house and Daytop models (New York). Later on, state-run clinics and advisory centres were implemented, since 1975 offering methadone maintenance treatment. The introduction of substitution treatment with oral methadone was a consequence of increasing numbers of addicts who failed in drug-free treatment and to the finding that only a small fraction of addicts was willing to accept long-term drug-free treatment in residential settings.  

During the eighties and nineties, the treatment system became more diversified and specialised. Outpatient treatment adapted psychotherapy to the needs of specific addicts, such as borderline patients and other dual diagnosis patients. Systemic therapy, especially family therapy in the case of adolescent addicts became a regular option. Specialised programmes for detoxification were set up, using diverse methods and settings. Residential long-term drug-free treatment introduced new concepts, in order to meet the needs for social re-integration in cases of severe social and educational deficits. Programmes for addicted couples and even families were developed. Also, religious orientation, the value of meditation techniques and similar approaches became an important issue.  

Overall, the treatment system increased the number of slots considerably : during the period 1985-1994, residential treatment increased by the twofold, methadone maintenance by the tenfold.


Harm reduction measures  

Following the AIDS epidemic (again with high prevalence rates, for many years the highest in Europe), risk reduction measures were – after controversial debates - accepted and introduced : syringe exchange schemes, injection rooms, low threshold day programmes. Also, experimentation with low-threshold methadone programmes started and resulted in well-established special clinics in major cities.  

Due to the abundant availability of drugs in the larger cities, addicts concentrated there and so-called open drug scenes emerged. At first, they were periodically repressed but re-emerged in different places, until they were tolerated in parks with comparatively little negative impact for the neighbourhood. Things deteriorated however, and the famous needle-parks in Zurich and Bern became intolerable centres of trafficking, associated delinquency and prostitution. A successful oppression of open drug scenes could only be realised through a concerted action between national, cantonal (provincial) and municipal authorities, and a combination of increased policy presence and an adequate availability of harm reduction measures, support structures and treatment opportunities outside of the larger cities (decentralised support and treatment. An essential additional measure was the “repatriation” of addicts coming from the countryside, from smaller cities and even from neighbouring countries (they made up for ca. 80% of addicts identified in open drug scenes in Zurich). Addicts injecting in public or otherwise identified were arrested and brought by police to a special detention centre, transferred to somatic or psychiatric treatment if needed, and otherwise shipped home to where they came from and handed over to the respective authorities. This resulted not only in a reduced influx of addicts, but also in an increased awareness of authorities that now had to take care of their addicts. Also, understanding for prevention activities increased. 


Treatment research  

Most of the therapeutic programmes and approaches for heroin addicts were new and of uncertain efficacy. Outcome evaluation and guidelines how to run treatment professionally were asked for. The resources invested into developing the treatment system called for some evidence on the good use of such resources. The National Fund for Scientific Research granted a large national study on outcome in the late seventies. Cohorts from residential treatment, from methadone clinics and from prisons were prospectively followed-up, and compared with a representative sample from the same age group in the general population. The study was able to evidence the positive outcome and a progressive “normalisation” of life-styles in the treated cohorts in contrast to the prison cohort (Uchtenhagen & Zimmer Höfler 1985). The results encouraged not only the development of treatment programmes, but also the referral of addicts from the Criminal Justice System to regular treatment agencies outside of the prison walls (the prison sentence being suspended and eventually reactivated in case of treatment failure). Referrals were at first made mainly to residential treatment, then in increasing numbers also to outpatient methadone maintenance programmes.  

The Federal Office of Public Health has since invested largely in treatment research regarding drug dependence and drug abuse. The Federal Drug Policy of 1991 not only stated the four pillars of policy (Prevention, treatment, harm reduction measures and repression), but also the will to evaluate measures in the interest of an evidence-based policy development. Reviews of treatment research have been published by the Federal Office of Public Health (Rihs-Middel & Lotti 1997).


Why heroin assisted treatment ?  

In spite of a good availability of therapeutic options, treatment refractory addicts were identified in the open drug scenes, responsible for an essential part of nuisance and drug-related delinquency. It was obvious that for this group new approaches had to be developed.  

The Amsterdam study on injectable morphine (Derks 1991) and the renewed British practice with injectable diamorphine (heroin) encouraged Swiss authorities and experts in this situation to prepare a national study with heroin-assisted treatment to those not responding to the existing treatment system.


Objectives and design of the experimental project (1994-1996)  

The main objectives of Heroin-assisted Treatment (HAT) were :  

- to recruit addicts into HAT who were not effectively reached by other treatment approaches

- to prevent premature dropping-out of HAT

- to reduce illegal / non prescribed substance use by HAT patients

- to improve health status and social integration of HAT patients (especially to reduce delinquency)

- to compare the effects of injectable diamorphine (heroin), methadone and morphine

- to facilitate transfer of HAT patients to regular treatment programmes.


Design :  

In order to determine outcome, the main study was set up as a longitudinal prospective study (cohort study), complemented by randomised and double blind sub-studies comparing injectable diamorphine, methadone and morphine.


Implementation of the project  

Target population  

According to the objectives, the new therapeutic approach should be open to heroin addicts who were chronically dependent (no beginners), who suffered from health and social problems as a consequence of their addiction (no unproblematic users) and who had without success engaged in other treatment programmes at least twice (HAT is not to be administered if nothing else has been tried before). Only addicts not younger than 18 years of age were targeted; younger adolescents should whenever possible receive drug-free treatment.  


Entry criteria  

The criteria for participating in the project therefore concerned a minimal age of 20 (later 18), documented dependence duration of minimal 2 years, documented health and/or social deficits and at least 2 previous treatments that failed. Also, compliance with the diagnostic, therapeutic and research programme was conditional.  Persons in possession of a driving licence were not allowed to drive and had to deposit their licence during the entire treatment period.  


Conditions for treatment provision 

HAT is available exclusively in authorised clinics. Each individual must have a permit to enter the programme, issued by the Federal Office of Public and by the responsible medical officer of the Canton where treatment takes place. Authorisation and permit can be revoked in case of non-compliance with rules.  

Administration of injectables has to be made by the patient under visual supervision of staff in the clinics. There is no take-home policy regarding injectables. Patients who are already intoxicated when presenting for an injection have to wait until they are in a normal state.ealth and by the cantonal medical officer  

Patients have to participate in the comprehensive assessment procedures and in the treatment programme. They must be ready for research interviews and urine checks although refusal is possible. At entry, they receive an information sheet and have to sign a form on informed consent. They can leave the programme at any time. They can be excluded temporarily or definitively when misbehaving and breaking the rules.  

Clinics have to keep case histories of all patients and have to perform the necessary clinical and laboratory tasks. They provide periodical reports to the Federal Office of Public Health.  

Logistics and storage of narcotics are strictly regulated and checked.



A detailed research protocol was set up and accepted by the Federal Government and by the national Ethics Committee of the Swiss Academy of Medical Sciences.   

The research protocol, the instruments and reports were prepared by an independent research team at the Addiction Research Institute and the Institute of Social and Preventive Medicine, both at Zurich University. Other research groups were charged with specific studies, such as the study on changes in delinquency rates (Institute of police science and criminology at Lausanne University) and the economic study on costs and benefits of HAT (Health Econ Institute in Basel).   

A safety assurance group of experts followed closely the side effects and untoward events occurring during the project and took appropriate steps if needed.  

Sources of information were face-to-face interviews by independent interviewers, observations by clinic staff, case histories of former treatments, laboratory findings and police data.  

The research team was guided by a national expert committee which monitored the research process and products. World Health Organisation set up an additional international expert committee which reviewed the protocol and instruments, monitored the process and evaluated the final report (Ali et al.1999).


Main results of the cohort study  

An extensive summary of the experimental project was published as a book (Uchtenhagen et al 1999). It contains outcome data on 1035 patients who entered HAT between 01.01.1994 and 30.06.1996.  

The feasibility of establishing Heroin Clinics in 14 cities with mixed national/local funding, with adequate staff and with a high degree of acceptance by authorities and the population could be assured. Only one clinic could not be realised as it was allowed to prescribe injectable morphine only, and not enough addicts were willing to enter this programme.  

Also, the safety of patients and staff could be evidenced (no fatal overdose from prescribed substances, no successful thefts or deviation to the illegal market, few cases of violent behaviour). In contrast to expectations, the daily dosages of diamorphine could not only be stabilised, but were slightly reduced over time. Many patients preferred to combine injectable diamorphine with oral methadone, in order to have more freedom to resume school attendance or employment.  

The systematic monitoring of side effects identified allergic reactions, sedation and epileptic seizures as the main side effects occurring after diamorphine injection. Seizures are related to a temporary insufficient oxygen saturation in the brain; they can be minimised by activation of patients after injections and by adequate medication in patients with a history of seizures. Side effects of injectable methadone were mainly painful sensations at the injection site, while injectable morphine produced more and more severe allergic reactions than diamorphine.  

The consumption of illegal / non-prescribed substances while being on the programme was reduced significantly (especially the daily use of heroin and cocaine, to a lesser degree the regular use of Benzodiazepines). Cannabis use on the other hand remained essentially unchanged, but without noticeable effect on treatment outcome.  

Health status  was significantly improved. Especially a reduction of depressive episodes and suicidal ideation, of epileptic attacks and of paranoid episodes was registered. Also, general physical health and nutritional health (body mass index) improved.  

Regarding social integration, it may be mentioned that homelessness was significantly reduced, while reintegration into the regular labour market proved to be more difficult. Most spectacular was the reduction of criminal activities according to self-report and police data (Killias & Rabasa 1998). Income from illegal activities was reduced accordingly, in part replaced by welfare payments.  

Retention in treatment was superior to what is observed in other forms of treatment (76% over a 12-month period). 60% of discharged patients could be transferred to a regular treatment programme within 18 months (about half of those to drug-free programmes).  

The cost-benefit analysis showed a considerable reduction in costs for medical care and law enforcement; the benefits per day and patient amount to the double of the daily treatment costs in HAT  (Frey et al 2000).  

Main results of the randomised and double-blind substudies  

The comparison of injectable diamorphine with injectable methadone and morphine came to the following results (Ladewig et al 1997, Hämmig & Tschacher 2001, Moldovanyi 2000) :  

Recruitability of patients into the diamorphine groups was superior. The groups for methadone and morphine did not reach the expected numbers, as many patients left after randomisation before starting treatment.  

Retention was superior in the diamorphine groups. This was evidenced in the randomised and in the double-blind studies. High dropout rates in the methadone and morphine groups was mainly due to the extent and gravity of side effects.  

Compliance with the programme, as measured by the extent of using illegal heroin and cocaine, was superior in the diamorphine groups.  

Overall, diamorphine was found to be more acceptable and effective in terms of retention and compliance than injectable methadone and morphine. Patients doing well on methadone and morphine were allowed to continue, but no new patients were offered this approach.


Follow-up studies  

A first systematic follow-up study, covering a period of 18 months since entry, was made in 1997. It included 237 patients who entered HAT from 1.1.94 to 31.3.1995 (Rehm et al 2001).  

The study documented highly significant reductions in somatic and psychiatric problems (during the first 6 months of treatment already, and being stable over the entire follow-up period). Improvements in the housing and employment situation, also significant, took more time to occur. Contacts to the illegal drug scene and living from illegal income were equally reduced (also during the first 6 months stabilised since). The reduction not only in daily illegal heroin use, but also in cocaine use was highly significant already in the first 6 months after entering treatment. 60% of discharged patients entered a regular drug-free or methadone programme.  

Additional analysis showed that improvements in discharged patients were related to time in treatment. Those who entered a regular programme at discharge showed better results than those who did not. Improvements were not reversed with increasing length of follow-up observation time.  

A special analysis concerned the progress of new blood-borne infections (HIV, Hepatitis B and Hepatitis C) during treatment. It found that new infections occurred, but at a low incidence rate much inferior to what is observed in untreated injecting addicts (Steffen et al. 2001)  

In 2000, a second systematic follow-up study was made (Güttinger, Gschwend et al, submitted). It included a patient sample of n=244 (entries up to 31.3.1995) and covered a period of 6 years. At that time, 46% of patients still were in treatment. 48% of discharged patients had entered a regular programme. A comparison of those still in treatment with those who were discharged showed :  

- a significant reduction in illegal heroin, cocaine and Benzodiazepine use in both groups

- no reduction in cannabis use in both groups

- a significant reduction of homelessness in both groups

- no reduction in unemployment in both groups

- a highly significant reduction in living from illegal income and in new court cases.  

The rate of patients who proceeded from HAT to drug-free treatment programmes increased during the first year of treatment and slightly decreased since.  



Heroin addicts for whom other treatment approaches had failed, can be recruited and retained in HAT to a satisfactory degree. Their health status and social integration can be significantly improved. Improvements are mainly stable, also in discharged patients. Side effects of prescribed diamorphine are comparatively few and manageable. No fatal overdose of prescribed substances occurred up to now. About half of discharged patients agreed to enter regular treatment programmes.  

These results are conditioned by restrictive entry criteria, by strict rules for running the authorised clinics and by a close monitoring of treatments by research. Those conditions therefore have been kept when establishing HAT as a regular treatment option by a Federal Decree.  

Diamorphine is registered under the name Diaphine as a medication for maintenance in heroin addicts since January 2002.A new legal basis for HAT by a revision of Narcotic Law is in preparation.  

When doing so, it is not the intention to replace other forms of treatment by HAT. On the contrary, it is considered to a valuable supplement to the already existing treatment system, with specific indications and specific precautions. A treatment system with adequate accessibility and quality is therefore an essential precondition for setting up HAT programmes.  

The WHO report (Ali et al 2000), while confirming the main findings of the Swiss cohort study, advocated continued research efforts, especially in order to determine the respective roles of diamorphine prescription and of concomitant care for positive outcome. Another international comment (Bammer et al 1999) came to a similar conclusion. The Dutch and German research projects on heroin-assisted treatment have taken up these comments and will bring further evidence. The Dutch project started on July 1998, and results will be known in March 2002. The German project will start in early 2002 and has a duration of 2 years.  



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