Clinical experiences with 959 opioid-dependent patients treated with levo-alpha-acetylmethadol (LAAM)

Pharmacological options for management of opioid dependence

Methadone is currently the only opioid available for the pharmacotherapy of opioid dependence. Cross-tolerance between methadone and other opioids constitutes the pharmacological basis for substitution and attenuating the effects of illicit opioid use. However, these principles limit the utility of methadone. Potential alternative opioids include long-acting partial agonists such as buprenorphine and pure antagonists such as naltrexone. Buprenorphine is an alternative to methadone with intermediate intrinsic efficacy. It has a large margin of safety, yet displays some agonist actions similar to methadone. It has greater potential than methadone to safely and effectively block the actions of illicit opioids. Naltrexone is a safe, convenient opioid-antagonist for use following detoxification from opioid agonists. Its main use is to block the actions of other opioids, thereby attenuating or eliminating illicit use during treatment. However, it is poorly accepted by many clients, limiting its application to a sub-group who are highly motivated to detoxify. The distinct pharmacological properties of these opioids can overcome some of the drawbacks of methadone, but other limitations may emerge. Non-opioid adjuncts such as alpha2-adrenoceptor agonists can also have a role during detoxification. These drugs might be of use for specific groups of opioid users, providing therapists with the flexibility to tailor pharmacotherapy to the individual needs of clients.

Self administration of cocaine in monkeys receiving LAAM acutely or chronically

Polydrug abuse remains a common problem among opioid abusers as well as patients in opioid maintenance programs. Although cocaine abuse has been reported in patients receiving methadone, the incidence of cocaine use in patients receiving l-alpha-acetylmethadol (LAAM) has not been well established. The goal of this study was to determine whether acute or chronic administration of LAAM modified the reinforcing effects of cocaine using a self-administration procedure in rhesus monkeys. Four monkeys responded under a fixed ratio (FR) 30 schedule to receive i.v. infusions of cocaine (0.0032-0.32 mg/kg/infusion) in the absence of other treatment, after acute LAAM administration (0.1-1.0 mg/kg, s.c.), and during daily administration of 1.0 mg/kg of LAAM. Cocaine maintained self-administration responding that exceeded responding maintained by saline; acutely administered LAAM had small and variable effects on self administration of cocaine. Daily LAAM administration increased the number of infusions received of at least one dose of cocaine. These studies indicated that LAAM administration did not attenuate the reinforcing effects of cocaine, suggesting that LAAM would not likely alter cocaine abuse in patients undergoing treatment for opioid abuse.

Combating opiate dependence: a comparison among the available pharmacological options

Pharmacotherapies for heroin addiction may target opiate withdrawal symptoms, facilitate initiation of abstinence and/or reduce relapse to heroin use either by maintenance on an agonist or antagonist agent. Available agents include opioid agonists, partial opioid agonists, opioid antagonists and alpha 2 -agonists for use during managed withdrawal and long-term maintenance. Experimental approaches combine alpha 2 -agonists with naltrexone to reduce the time of opiate withdrawal and to accelerate the transition to abstinence. Recently, buprenorphine has been introduced in the US for office-based maintenance, with the hope of replicating the success of this treatment in Europe and Australia. Naloxone has been added to buprenorphine in order to reduce its potential diversion to intravenous use, whilst facilitating the expansion of treatment. Although comprehensive substance abuse treatment is not limited to pharmacotherapy, this review will focus on the rationale, indications and limitations of the range of existing medications for detoxification and relapse prevention treatments. The two major goals of pharmacotherapy are to relieve the severity of opiate withdrawal symptoms during the managed withdrawal of the opioid and to prevent relapse to heroin use either after abstinence initiation or after being stabilised on a long-acting opiate agonist, such as methadone.

Evaluation of levo-alpha-acetylmethdol (LAAM) as an alternative treatment for methadone maintenance patients who regularly experience withdrawal: a pharmacokinetic and pharmacodynamic analysis

The aim of this study was to determine if substitution of daily methadone with second daily levo-alpha-acetylmethadol (LAAM) would convert non-holders on methadone into holders on LAAM, and to compare plasma concentration-time profiles of (R)-methadone with LAAM and its two metabolites. Sixteen stable methadone maintenance treatment participants (non-holders, n = 8) were randomly allocated to continue methadone for 3 months or switch to LAAM for 3 months, and then crossed over to the alternative drug for 3 months. At steady state, there were two testing sessions (24 h for methadone and 48 h for LAAM), during which opioid withdrawal severity, respiration rate and pupil diameter were measured 10-11 times and venous blood was collected 13-15 times. Ten age- and gender-matched controls underwent one 48-h test session. Areas under the withdrawal severity score versus time curve (AUC(0-47) hours for LAAM and controls; AUC(0-24) x 2 for methadone) were similar in holders on methadone and LAAM (P = 0.62), but were greater in non-holders when they were taking methadone than LAAM (P < 0.001). Respiratory depression and pupillary constriction were similar for LAAM and methadone. In comparison to (R)-methadone, plasma nor- and dinor-LAAM concentrations fluctuated little over the dosing interval. LAAM converted methadone non-holders into LAAM holders. LAAM may therefore be useful in selected MMT non-holders and improve retention in opioid treatment programs.

Serious adverse events in the Australian National Evaluation of Pharmacotherapies for Opioid Dependence (NEPOD)

AIMS

The study estimated serious adverse event (SAE) rates among entrants to pharmacotherapies for opioid dependence, during treatment and after leaving treatment.

DESIGN

A longitudinal study based on data from 12 trials included in the Australian National Evaluation of Pharmacotherapies for Opioid Dependence (NEPOD).

PARTICIPANTS AND SETTINGS

A total of 1244 heroin users and methadone patients treated in hospital, community and GP settings. Intervention Six trials included detoxification; all included treatment with methadone, buprenorphine, levo-alpha-acetyl-methadol (LAAM) or naltrexone.

FINDINGS

During 394 person-years of observation, 79 SAEs of 28 types were recorded. Naltrexone participants experienced 39 overdoses per 100 person-years after leaving treatment (44% occurred within 2 weeks after stopping naltrexone). This was eight times the rate recorded among participants who left agonist treatment. Rates of all other SAEs were similar during treatment versus out of treatment, for both naltrexone-treated and agonist-treated participants. Five deaths occurred, all among participants who had left treatment, at a rate of six per 100 person-years. Total SAE rates during naltrexone and agonist treatments were similar (20, 14 per 100 person-years, respectively). Total SAE and death rates observed among participants who had left treatment were three and 19 times the corresponding rates during treatment.

CONCLUSIONS

Individuals who leave pharmacotherapies for opioid dependence experience higher overdose and death rates compared with those in treatment. This may be due partly to a participant self-selection effect rather than entirely to pharmacotherapy being protective. Clinicians should alert naltrexone treatment patients in particular about heroin overdose risks. Duty of care may extend beyond cessation of dosing.

Effects of 2beta-propanoyl-3beta-(4-tolyl)-tropane (PTT) on the self-administration of cocaine, heroin, and cocaine/heroin combinations in rats

Pharmacotherapies utilizing long-acting agonists and mixed function agonists-antagonists have been successful in the treatment of opiate addiction but no comparable treatment exists for cocaine abuse. Long-acting tropane analogues have been synthesized that could be candidates for such pharmacotherapies. 2beta-propanoyl-3beta-(4-tolyl)-tropane (PTT) is one such compound that is a relatively selective dopamine (DA) transporter blocker that has a significantly longer duration of action than cocaine. The purpose of this study was to assess the effects of PTT on the intravenous self-administration of cocaine, heroin, or cocaine/heroin combinations. Groups of rats were trained to self-administer cocaine, heroin, or cocaine/heroin combinations using a within session dosing procedure in which three doses were available each session. PTT pretreatment reduced cocaine and cocaine/heroin combinations intake in a dose-dependent manner while having only minor effects on heroin intake. These results suggest that the neurobiological substrates of cocaine and heroin self-administration are different, and that these cocaine/heroin combinations may function more like cocaine alone, even when the dose of heroin in the mixture will function independently as a reinforcer. These results further support the potential use of long-acting dopamine reuptake inhibitors as pharmacotherapeutic adjuncts to a comprehensive treatment program for cocaine and cocaine/heroin abuse.

Substitution management in opioid dependence

Substitution treatment (replacement therapy) is the most widespread and the most frequently researched therapeutic approach to heroin dependence. At present, the "gold standard" is methadone maintenance, but the use of other agonists and of combined compounds with antagonists are increasingly used, especially Buprenorphine. This paper reviews the main findings from research and their consequences for best practice rules. The evolution and organisation of substitution treatment in Europe is described, indicating a major discrepancy in administrative regulations. Emerging trends are also mentioned, as well as the merits and limitations that mark the place of substitution treatment in a comprehensive therapeutic network for opioid dependence.

Treatment of heroin (diamorphine) addiction: current approaches and future prospects

New pharmacological treatments for heroin (diamorphine) addiction include drugs that reduce opiate withdrawal symptoms and agents that are given during the maintenance phase of treatment. A variety of different types of pharmacological agents (opioid agonists, partial opioid agonists, opioid antagonists and alpha(2)-adrenoreceptor agonists) are reviewed and the evidence of their use during managed withdrawal and maintenance are presented. Experimental approaches attempting to reduce the time of opiate withdrawal and to accelerate the transition to abstinence are being developed. The combination tablet of buprenorphine and naloxone that is to be introduced for office-based maintenance is currently undergoing intense evaluation in the US. This new approach may facilitate the expansion of treatment while reducing the potential for medication diversion and intravenous use.

Relationship between LAAM-methadone preference and treatment outcomes

Studies of relative LAAM-methadone preference have indicated that a significant proportion of patients prefer levo-alpha-acetylmethadol (LAAM). The present study was designed to determine whether this preference is associated with better treatment outcomes. Sixty-two stable methadone patients participated in a randomised crossover clinical trial. They received LAAM (alternate days) and methadone (daily) for 3 months each, followed by a further 6-month period during which they were free to choose between the drugs. LAAM maintenance was associated with a lower rate of heroin use than methadone maintenance based on analysis of morphine concentration in hair and equivalent health outcomes. The majority of subjects showed a preference for LAAM (n=27, 69.2%) rather than methadone (n=12, 30.8%). The main reasons given for the LAAM preference were that it produced less withdrawal (39.3%), fewer side effects (28.5%), less craving for heroin (17.9%), and entailed fewer pick-up days (14.3%). Those who chose LAAM had lower levels of heroin use during LAAM maintenance, significantly better outcomes on two sub-scales of the SF-36 (Vitality and Mental Health), and reported that they felt more normal and that they were 'held' better when on LAAM. For those who chose methadone, there were no differences in outcomes between the LAAM and methadone maintenance periods. Preference for LAAM is associated with treatment outcomes as good or better than those with methadone.

LAAM maintenance vs methadone maintenance for heroin dependence

BACKGROUND

LAAM and methadone are both full mu opiate agonists and have been shown to reduce dependence on heroin when given continuously under supervised dosing conditions. LAAM has a long duration of action requiring dosing every two or three days compared to methadone which requires daily dosing. LAAM is not as widely available internationally as methadone, and may be withdrawn from the market following ten cases of life-threatening cardiac arrhythmias and an association with QT prolongation.

OBJECTIVES

To compare the efficacy and acceptability of LAAM maintenance with methadone maintenance in the treatment of heroin dependence.

SEARCH STRATEGY

We searched MEDLINE (January 1966 to August 2000), PsycINFO (1887 to August 2000), EMBASE (January 1985 to August 2000), and the Cochrane Controlled Trials Register (Issue 2 2000). In addition we hand searched NIDA monographs until August 2000 and searched reference lists of articles.

SELECTION CRITERIA

All randomised controlled trials, controlled clinical trials and controlled prospective studies comparing LAAM and methadone maintenance for the treatment of heroin dependence and measuring outcomes of efficacy or acceptability were included.

DATA COLLECTION AND ANALYSIS

Data on retention in treatment, heroin use, side-effects and mortality were collected by two reviewers independently. A meta-analysis was performed using RevMan. Discrepancies were resolved by consensus.

MAIN RESULTS

Eighteen studies, (15 RCTs, 3 Controlled prospective studies) met the inclusion criteria for the review. Three were excluded from the meta-analysis due to lack of data on retention, heroin use or mortality. Cessation of allocated medication (11 studies, 1473 participants) was greater with LAAM than with methadone, (RR 1.36, 95%CI 1.07-1.73, p=0.001, NNT=7.7 (or 8)). Non-abstinence was less with LAAM (5 studies, 983 participants; RR 0.81, 95%CI 0.72-0.91, p=0.0003, NNT=9.1 (or 10)). In 10 studies (1441 participants) there were 6 deaths from a range of causes, 5 in participants assigned to LAAM (RR 2.28 (95%CI 0.59-8.9, p=0.2). other relevant outcomes, such as quality of life and criminal activity could not be analysed because of lack of information in the primary studies.

REVIEWER'S CONCLUSIONS

LAAM appears more effective than methadone at reducing heroin use. More LAAM patients than methadone ceased their allocated medication during the studies, but many transferred to methadone and so the significance of this is unclear. There was no difference in safety observed, although there was not enough evidence to comment on uncommon adverse events.

Drug treatment for women: traditional models and new directions

Drug treatment is a diverse field in which a variety of treatment frameworks and formats exist, few of which have been tailored to women's circumstances and needs. Most drug treatment is based on insight-oriented and behavioral approaches, often accompanied by pharmacologic treatments. Complementary approaches such as acupuncture and biofeedback also are available. Feminist criticisms of traditional therapy have prompted development of woman-centered treatment, which provides a safe environment for empowerment and building relationship skills. Nurses can provide supportive interventions using mutuality and avoiding confrontation, and can advocate for access to woman-centered drug treatment and harm reduction measures to minimize the damage caused by alcohol and drugs.

Levo-alpha-acetylmethadol (LAAM): clinical, research, and policy issues of a new pharmacotherapy for opioid addiction

A number of issues are relevant to the development and use of levo-alpha-acetylmethadol (LAAM) as a treatment alternative to methadone. A brief history of methadone maintenance treatment is provided and variants of standard methadone treatment are discussed. The history and current status of LAAm are discussed, as well as its advantages over methadone. In addition, relevant clinical, research, and policy issues are addressed. LAAm has advantages over methadone specifically with regard to thrice-weekly dosing, potential to reduce HIV/AIDS risk, possible cost savings, and possible improved clinic-community relations. The effective and cost-effective implementation of LAAM as a new treatment for opioid addiction requires attention to a number of issues: (1) LAAM as an HIV prevention measure through its potential risk-reduction effects, (2) the sue of LAAM with specific high-risk subgroups, (3) causes of differential rates of treatment dropout and their amenability to intervention, (4) the role fo patient choice in long-term maintenance treatment, (5) the impact of LAAM on clinic operations, (6) the potential for LAAM as a take-home medication, and (7) the costs of implementing and sustaining LAAM maintenance services.

Methadone maintenance treatment in opiate dependence: a review

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Substitution pharmacotherapies for opioid addiction: from methadone to LAAM and buprenorphine

The efficacy and cost-effectiveness of opioid substitution therapy for the treatment of opioid addiction has been well documented within the methadone maintenance model for over thirty years. However, methadone does not meet the specific treatment needs of all opioid-dependent persons who might benefit from substitution therapy; consequently, a significant proportion of heroin addicts remain untreated. The recent approval of l-alpha-acetylmethadol (LAAM) as a maintenance treatment agent represents the first opioid substitution alternative to methadone. LAAM is a fundamentally different medication than methadone, with unique pharmacological characteristics. Its use requires a different approach to the clinical management of opioid substitution therapy and a different medication delivery strategy. The availability of LAAM has potential important implications for patients, clinics, and the community at large. Full realization of its advantages could move opioid substitution therapy into mainstream medical care and draw into treatment a substantial number of new patients able to benefit from such treatment. Buprenorphine, the other new opioid substitution therapy under development, shares some common advantages with LAAM. Its high safety profile and low physical dependence liability make it uniquely suitable for a subset of addicts as well as an initial treatment of choice in the opioid substitution treatment armamentarium.

Opioid addiction treatment modalities and some guidelines to their optimal use

Opioid addiction treatment consists of a broad range of treatment modalities, with each playing a valuable role within the overall network of treatment alternatives. Therapeutic communities are often the treatment of choice for addicts who are under legal contingencies and amenable to a rigorous process of life-style change. Methadone maintenance offers the most widely available treatment and is a modality that is compatible with the needs of many injecting heroin users. Outpatient drug-free models offer structure and support to detoxified opioid addicts and nonaddicted opioid abusers. New pharmacotherapies, including clonidine, LAAM, naltrexone and buprenorphine, provide promise for addressing the needs of many opioid abusers who are not currently accessing the treatment system. Furthermore, the treatment system could be better utilized if treatment planning was based more on the needs of the addict than on the ideological bias of the clinician; training efforts could be useful in facilitating change in clinician attitudes.

The Management of Opiate Abuse: Learning from other Addictions

Similarities between the addictions suggest that much may be learned about the management of opiate abuse from a study of the problems and results of treatment in other types of compulsive or addictive behavior. Medical methods of treatment, notably methadone, laevo-alpha acetyl methadole, naltrexone and random urine screening, may make a useful contribution to improvements in the outcome of mandatory programs when combined with close supervision, and a rapid and predictable response to lack of compliance. Some important features of a model treatment program are suggested.