THE WESTERN SYDNEY AREA HEALTH SERVICE NALTREXONE PROJECT RAPID INDUCTION ONTO NALTREXONE A RANDOMIZED CLINICAL TRIAL OF ANESTHESIA - ASSISTED VERSUS SEDATION - ASSISTED TECHNIQUES, AND A COMPARISON WITH CONVENTIONAL DETOXIFICATION
Investigators: Dr Jon Currie, MBBS FRACP Director, WSAHS Drug and Alcohol Services Dr Lisa Collins, PhD WSAHS Drug and Alcohol Services Dr Yugan Mudaliar, MB ChB FCP (SA) FFARACS FRACP Director of Intensive Care Unit, Westmead Hospital Dr Peter Cox, MBBS, FANZCA, FFPMANZCA Visiting Medical Officer, Departments of Anesthesia and Chronic Pain Services, Westmead Hospital Ms Lorraine Gaunt, CNS, BA HSc (Nursing) WSAHS Drug and Alcohol Services Ms Patricia Lutz, CNC, RGN, RPN, Grad Cert Public Health (Add) Consultation / Liaison Services, WSAHS Drug and Alcohol Services Ms Harriet Ward, A/ADON, RMN, BN, Masters Adult Ed WSAHS Drug and Alcohol Services Correspondence to: Dr Jon Currie Western Sydney Area Health Service Drug and Alcohol Service Clinic E, Westmead Hospital, Westmead, NSW 2145. Telephone: (02) 9845 6445 Fax: (02) 9635 8771 Email EXECUTIVE SUMMARY 1. OBJECTIVES The project was divided into two phases, each with separate aims. PHASE 1: INDUCTION ONTO NALTREXONE Aims: (1)
Through a randomized clinical trial, to compare the techniques of:
anesthesia-assisted rapid induction onto naltrexone, and sedation-assisted rapid induction onto naltrexone efficacy of successful induction onto naltrexone patient safety patient acceptability operational feasibility service costs within the public health system.
To compare the techniques of anesthesia-assisted and sedation-assisted rapid induction onto naltrexone (RION) with conventional naltrexone induction following conventional detoxification for: the efficacy of successful induction onto naltrexone and service costs within the public health system. PHASE 2: NALTREXONE-SUPPORTED MAINTENANCE OF ABSTINENCE Aims: (1)
To examine the role of naltrexone pharmacotherapy in supporting abstinence maintenance programs, and to develop clinical guidelines for its optimal use in such programs within the Australian public health system.
To determine what influence, if any, using RION techniques has on the long-term clinical outcomes of naltrexone-supported abstinence maintenance programs over the 12 month period following induction.
2. PATIENT DEMOGRAPHICS A combined total of 150 patients were enrolled into the study male n = 90; female n = 60 mean age = 30.5 years. Heroin-dependent (n = Methadone-dependent (n = mean age (years) mean duration of opiate use (years) mean daily opiate dose (mg) 3. PROTOCOLS FOR INDUCTION ONTO NALTREXONE
Anesthesia-assisted RION n = 47 Sedation-assisted RION n = 70 Conventional induction following conventional detoxification n = 33
4. OUTCOMES PHASE 1: INDUCTION ONTO NALTREXONE Rates for Successful Induction Onto Naltrexone anesthesia-assisted RION = 98% sedation-assisted RION = 99% conventional inpatient detoxification / induction = 37% conventional ambulatory detoxification / induction = 17% There were no significant differences in the rates of successful induction between the anesthetic and the sedation-assisted RION techniques, nor between the heroin and the methadone patient subgroups. The difference in rates of successful induction between RION and conventional techniques was statistically significant. Rapid Induction: Mean Duration of Inpatient Stay
anesthesia-assisted RION = 1.5 days sedation-assisted RION = 1.8 days
Rapid Induction: Patient Satisfaction / Acceptance of Procedure “If necessary, would you have the procedure again” or “would you recommend it to a friend”. RELATIVE COST PER SUCCESSFUL INDUCTION ONTO NALTREXONE anesthesia-assisted RION = $2005 sedation-assisted RION = $1985 conventional inpatient detoxification / induction = $6656 conventional ambulatory detoxification / induction = $5541
PHASE 2: NALTREXONE-SUPPORTED MAINTENANCE OF ABSTINENCE Outcomes after 12 months follow-up: Remaining in medical treatment (Combines “non-dependent on opiates” and “commenced / recommenced methadone maintenance”) Heroin = 75% Methadone = 87% Known or presumed to have relapsed to dependent heroin use
Heroin = 25% Methadone = 13% Proven non-dependent on opiates Heroin = 59% Methadone = 62% Commenced / recommenced on methadone maintenance Heroin = 16% Methadone = 25% The long-term clinical outcomes were INDEPENDENT of the technique used to achieve induction onto naltrexone, and there were no significant differences in the clinical outcomes for rapid versus conventional induction. The long-term outcomes are primarily a reflection of the quality of the abstinence maintenance program and not the method used to achieve induction onto naltrexone.
Patients who resided in REGIONAL NSW were geographically isolated from the metropolitan Sydney-based rehabilitation program and had significantly higher rates of relapse to heroin use.
Relapse rates: · regional NSW = 80% metropolitan Sydney = 25% Rapid induction and abstinence maintenance services should be established locally in the areas from which the patients come, rather than developing centralized specialist facilities to which patients must travel long distances. MORTALITY WITHIN THE PROGRAM Four patients who relapsed to opiate use subsequently died from opiate overdoses. In all cases this occurred at least 14 days after their last prescribed dose of naltrexone. 5. CONCLUSIONS AND RECOMMENDATIONS 1)
Within the public health system, the techniques for rapid induction onto naltrexone (RION) developed in this project are:
The cost per successful induction onto naltrexone is significantly less for the rapid induction techniques than for conventional detoxification techniques. Rapid induction onto naltrexone is a cost-effective method for commencing abstinence maintenance within the public health system.
RION techniques and naltrexone-supported abstinence maintenance are just one aspect of a broad spectrum of available options for treating opiate dependence, including opiate substitution through methadone maintenance. It is important that at any particular time, patients are matched to the treatment option that is most appropriate for them at that time, and this should be achieved through ongoing monitoring of clinical progress.
RION treatment procedures should not be conducted in stand-alone facilities, but should only be available within clinical services where most or all treatment options, including methadone maintenance, are available intercurrently.
Regional NSW-based patients who travelled to western Sydney for the RION procedure had markedly higher relapse rates within the first month of follow-up, and subsequently across the whole 12 month period of follow-up.
RION and abstinence maintenance services should be established locally rather than as a centralized specialist facility that is geographically remote from the patients it serves.
Outcomes from the sedation-assisted RION technique are equal to or superior to those from the anesthesia-assisted RION technique, and the risk-to-benefit ratio for the sedation technique is much lower. It is recommended that the anesthesia-assisted rapid induction technique be discontinued. Sedation-assisted rapid induction onto naltrexone should be performed within a dedicated inpatient high dependency environment, utilizing a specifically trained and experienced nursing and medical team, with post-induction inpatient monitoring performed for at least 24 hours. Once successful induction onto naltrexone is achieved, the clinical outcomes are INDEPENDENT of the method used to achieve that induction (ie anesthesia RION vs sedation RION vs conventional detoxification). The long-term outcomes are therefore dependent upon the quality of the abstinence maintenance program, not upon the method of induction onto naltrexone. To optimize retention and compliance within naltrexone-supported abstinence maintenance programs, novel programs with relatively naltrexone-specific structure and content need to be developed.
Naltrexone-supported abstinence maintenance treatment achieves clinically useful results for both heroin and methadone-dependent patients who wish to undertake an abstinence-based lifestyle. Naltrexone-supported maintenance of abstinence is therefore an additional treatment option that should be available through the public health system at an Area Health Service level. All patients who are seeking to undertake an abstinence-based model of treatment should be offered the option of assistance through naltrexone-supported maintenance.
For patients who wish to cease METHADONE treatment and become abstinent, sedation- assisted rapid induction onto naltrexone, followed by a naltrexone-supported abstinence maintenance program is one of the most effective treatment modalities currently available in Australia. This program should now be used to establish a methadone-to-abstinence clinical service within Western Sydney Area Health Service for long-term methadone patients wishing to exit their methadone maintenance program. This clinical service should be developed as a demonstration project for the Drug Treatment Services Plan and should incorporate a comprehensive service evaluation. Direct access to RION and naltrexone-supported abstinence maintenance programs through public sector methadone programs will also greatly enhance the acceptability of, and uptake into methadone maintenance for heroin-dependent patients, and will facilitate progression through the program and eventual exit from methadone maintenance when this is clinically indicated for stable long-term patients. For HEROIN-dependent patients, a demonstration project under the Drug Treatment Services Plan should now be developed that includes both a rapid induction program and the existing WSAHS detoxification services, (i) to undertake a service restructuring to incorporate naltrexone induction and naltrexone- supported abstinence maintenance into mainstream service delivery, (ii) to evaluate the effects this has on current service delivery and outcomes, and (iii) to develop best practice guidelines for such programs within the public hospital sector.
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r 3 ^ F o ™ e l n ' m e i s t f a r b i 8 Landes-Lehrer-ßibliothek des Fürstentums Liechtenstein Georg Thieme Verlag Stuttgart • New York 1987 Inhaltsverzeichnis Vorwort zur 11. Auflage V Generelle Prinzipien 1 Kapitell 1. Aufgaben der Pharmakologie 1 2. Heuristische Prinzipien in der Pharmakologie 2 2.1 Rezepttheorie 3 2.2 Struktur-Wirkungs-Beziehungen 6 2.3 Rezepto