Heroin Assisted Treatment for Opiate Addicts – The Swiss Experience

 Ambros Uchtenhagen


The heroin epidemic, starting in the early 70ties, led to an estimated number of 30‘000-40'000 addicts. This elevated prevalence is in line with a high addiction liability in our population also for alcohol, tobacco and prescription drugs.

The therapeutic response to the drug epidemic was at first initiated by NGO’s, setting up Therapeutic Communities of the day-top model. Later on, state-run clinics and advisory centers were implemented, since 1975 offering Methadon maintenance treatment. Following the AIDS epidemic (gain with high prevalence rates), risk reduction measures were accepted and introduced : syringe exchange schemes, injection rooms, and low threshold day programs. Convicted addicts were referred from the Criminal Justice System to the Therapeutic System (residential and out-patient) in increasing numbers. 

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. The Amsterdam study on injectable Morphine and the renewed British practice with injectable Diamorphine (Heroin) encouraged Swiss authorities and experts 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 Heroin (Diamorphine), Methadone and Morphine

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

In order to determine outcome, the main study was designed as a longitudinal prospective study (cohort study), complemented by randomized and double blind sub studies comparing injectable Heroin, Methadone and Morphine. Entry criteria concerned minimal age of 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 program was conditional.   

Sources of information were face-to-face interviews by independent interviewers, observations by clinic staff, and case histories of former treatments, laboratory findings and police data. The research protocols, instruments and reports were made by an independent research team, guided by a national expert committee and evaluated by an international expert committee nominated by WHO.


Main results of the cohort study 

An extensive summary of the experimental project was published as a book (Uchtenhagen et al : Prescription of narcotics to heroin addicts. Karger Basel 1999).  

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. 

Also, the safety of patients and staff could be evidenced (no fatal overdose from prescribed substances, no thefts or deviation to the illegal market, few cases of violent behavior). 

The consumption of illegal / non-prescribed substances was reduced significantly (especially the daily use of Heroin and Cocaine, to a lesser degree the regular use of Benzodiazepines, no significant reduction of Cannabis use). 

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

Regarding social integration, it may be mentioned that homelessness was significantly reduced, while reintegration into the regular labor market proved to be more difficult. Most spectacular was the reduction of criminal activities according to self-report and police data.  

Retention in treatment was superior to what is observed in other forms of treatment. 60% of discharged patients could be transferred to a regular treatment program (about half of those to drug-free programs). 

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.


Main results of the randomized and double-blind sub studies 

 The comparison of injectable Diamorphine with injectable Methadone and Morphine came to the following results : 

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 randomization before starting treatment. 

Retention was superior in the Diamorphine groups. This was evidenced in the randomized and in the double-blind studies. High dropout rates in the Methadone and Morphine groups were mainly due to the extent and severeness of side effects. 

Compliance with the program, 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 I.V. Methadone and Morphine. Patients doing well on Methadone and Morphine were allowed to continue this medication; no new patients however 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. It was published recently (Rehm et al : Feasibility, safety and efficacy of injectable heroin prescription for refractory opioid addicts : a follow-up study. The Lancet 158:1417-1420). 

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 stabilized 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 Ur Methadone program. 

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

In 2000, a second systematic follow-up study was made (Güttinger, Gschwend et al, in press). It included the same patient sample (n=244) 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 program. A comparison of those still in treatment with those who were discharged showed : 

-  a highly 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 HSAT to drug-free treatment programs, increased during the first year of treatment and slightly decreased since. Overall, there is no evidence of a general chronification of patients receiving injectable diamorphine.



Heroin addicts for whom other treatment approaches had failed, can be recruited und retained in HAT. 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 programs. 

These results are conditioned to restrictive entry criteria, to strict rules for running the authorized clinics and to 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 as a medication for maintenance in heroin addicts.

Back to top