Methadyl acetate (LAAM) in the treatment of heroin addicts. II. Double-blind comparison of gradual and abrupt detoxification

Oral naltrexone maintenance treatment for opioid dependence

BACKGROUND

Research on clinical application of oral naltrexone agrees on several things. From a pharmacological perspective, naltrexone works. From an applied perspective, the medication compliance and the retention rates are poor.

OBJECTIVES

To evaluate the effects of naltrexone maintenance treatment versus placebo or other treatments in preventing relapse in opioid addicts after detoxification.

SEARCH STRATEGY

We searched: Cochrane Central Register of Controlled Trials (CENTRAL - The Cochrane Library issue 6 2010), PubMed (1973- June 2010), CINAHL (1982- June 2010). We inspected reference lists of relevant articles and contacted pharmaceutical producers of naltrexone, authors and other Cochrane review groups.

SELECTION CRITERIA

All randomised controlled clinical trials which focus on the use of naltrexone maintenance treatment versus placebo, or other treatments to reach sustained abstinence from opiate drugs

DATA COLLECTION AND ANALYSIS

Three reviewers independently assessed studies for inclusion and extracted data. One reviewer carried out the qualitative assessments of the methodology of eligible studies using validated checklists.

MAIN RESULTS

Thirteen studies, 1158 participants, met the criteria for inclusion in this review.Comparing naltrexone versus placebo or no pharmacological treatments, no statistically significant difference were noted for all the primary outcomes considered. The only outcome statistically significant in favour of naltrexone is re incarceration, RR 0.47 (95%CI 0.26-0.84), but results come only from two studies. Considering only studies were patients were forced to adherence a statistical significant difference in favour of naltrexone was found for retention and abstinence, RR 2.93 (95%CI 1.66-5.18).Comparing naltrexone versus psychotherapy, in the two considered outcomes, no statistically significant difference was found in the single study considered.Naltrexone was not superior to benzodiazepines and to buprenorphine for retention and abstinence and side effects. Results come from single studies.

AUTHORS' CONCLUSIONS

The findings of this review suggest that oral naltrexone did not perform better than treatment with placebo or no pharmacological agent with respect to the number of participants re-incarcerated during the study period. If oral naltrexone is compared with other pharmacological treatments such as benzodiazepine and buprenorphine, no statistically significant difference was found. The percentage of people retained in treatment in the included studies is however low (28%). The conclusion of this review is that the studies conducted have not allowed an adequate evaluation of oral naltrexone treatment in the field of opioid dependence. Consequently, maintenance therapy with naltrexone cannot yet be considered a treatment which has been scientifically proved to be superior to other kinds of treatment.

Oral naltrexone maintenance treatment for opioid dependence

BACKGROUND

Research on the clinical application of oral naltrexone agrees on several things. From a pharmacological perspective, naltrexone works. From an applied perspective, however, the medication compliance and the retention rates are very poor.

OBJECTIVES

To evaluate the effects of naltrexone maintenance treatment versus placebo or other treatments in preventing relapse in opioid addicts after detoxification.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL - The Cochrane Library issue 6 2010), PubMed (1973- June 2010), CINAHL (1982- June 2010). We inspected reference lists of relevant articles and we contacted pharmaceutical producers of naltrexone, authors and other Cochrane review groups.

SELECTION CRITERIA

All randomised and controlled clinical trials which focus on the use of naltrexone maintenance treatment versus placebo, or other treatments to reach sustained abstinence from opiate drugs

DATA COLLECTION AND ANALYSIS

Three reviewers independently assessed studies for inclusion and extracted data. One reviewer carried out the qualitative assessments of the methodology of eligible studies using validated checklists.

MAIN RESULTS

Thirteen studies, 1158 participants, met the criteria for inclusion in this review.Comparing naltrexone versus placebo or no pharmacological treatments, no statistically significant difference were noted for all the primary outcomes considered. The only outcome statistically significant in favour of naltrexone is re incarceration, RR 0.47 (95%CI 0.26-0.84), but results come only from two studies.Comparing naltrexone versus psychotherapy, in the two considered outcomes, no statistically significant difference was found in the single study considered.Naltrexone was not superior to benzodiazepines and to buprenorphine for retention and abstinence and side effects. Results come from single studies.

AUTHORS' CONCLUSIONS

The findings of this review suggest that oral naltrexone did not perform better than treatment with placebo or no pharmacological agent with respect to the number of participants re-incarcerated during the study period. If oral naltrexone is compared with other pharmacological treatments such as benzodiazepine and buprenorphine, no statistically significant difference was found. The percentage of people retained in treatment in the included studies is however low (28%). The conclusion of this review is that the studies conducted have not allowed an adequate evaluation of oral naltrexone treatment in the field of opioid dependence. Consequently, maintenance therapy with naltrexone cannot yet be considered a treatment which has been scientifically proved to be superior to other kinds of treatment.

Males and females differ in response to opioid agonist medications

Few clinical trials include sex as a factor. This analysis explored within-sex differences in response to opioid agonist medications. Males and females randomly assigned to buprenorphine, LAAM, or methadone were compared on opioid use and retention in treatment. Females receiving buprenorphine had less objective drug use than females receiving methadone, while males receiving LAAM had less objective drug use than males receiving buprenorphine. Retention in treatment was longer for both sexes receiving methadone versus LAAM. Within-subject change results indicate that all three medications benefit both sexes. Clinical trials should be designed to examine the impact of sex on outcomes.

Oral naltrexone maintenance treatment for opioid dependence

BACKGROUND

Research on the clinical application of oral naltrexone agrees on several things. From a pharmacological perspective, naltrexone works. From an applied perspective, however, this medication is not used since the medication compliance and the retention rates are very poor.

OBJECTIVES

To evaluate the effects of naltrexone maintenance treatment versus placebo or other treatments in preventing relapse in opioid addicts after detoxification.

SEARCH STRATEGY

We searched the Cochrane Drugs and Alcohol Group Register of Trials (January 2005), Cochrane Central Register of Controlled Trials (CENTRAL - The Cochrane Library Issue 1, 2005), MEDLINE (1973-first year of naltrexone use in humans- January 2005), EMBASE (1974- January 2005), PsycINFO (OVID-January 1985 to January 2004). We inspected reference lists of relevant articles and we contacted pharmaceutical producers of naltrexone, authors and other Cochrane review groups.

SELECTION CRITERIA

All randomised and controlled clinical trials which focus on the use of naltrexone maintenance treatment versus placebo, or other treatments to reach sustained abstinence from opiate drugs

DATA COLLECTION AND ANALYSIS

Three reviewers independently assessed studies for inclusion and extracted data. One reviewer carried out the qualitative assessments of the methodology of eligible studies using validated checklists.

MAIN RESULTS

Ten studies, 696 participants, met the criteria for inclusion in this review. Only two studies described an adequate allocation concealment. The results show that naltrexone maintenance therapy alone or associated with psychosocial therapy is more efficacious that placebo alone or associated with psychosocial therapy in limiting the use of heroin during the treatment (RR 0,72 95% confidence interval 0.58 to 0.90). If we consider only the studies comparing naltrexone with placebo, the difference do not reach the statistical significancy, RR 0.79 (95%CI 0.59 to 1.06). With respect to the number of participants re incarcerated during the study period, the naltrexone associated with psychosocial therapy is more effective than the psychosocial treatment alone; RR 0.50 (95%CI 0.27 to 0.91). No statistically significant benefit was shown in terms of retention in treatment, side effects or relapse results at follow-up for any of the considered comparisons.

AUTHORS' CONCLUSIONS

Unfortunately the studies did not provide an objective evaluation of naltrexone treatment in the field of opioid dependence. The conclusions are also limited due to the heterogeneity of the trials both in the interventions and in the assessment of outcomes.

A systematic review on the efficacy of naltrexone maintenance treatment in opioid dependence

AIM

To evaluate the efficacy of naltrexone maintenance treatment in preventing relapse in opioid addicts after detoxification.

DESIGN

A systematic review according to the methodology developed by the Cochrane Collaboration based on either randomized controlled trials (RCTs) or controlled clinical trials (CCTs).

PARTICIPANTS

Seven hundred and seven heroin dependent in- and out-patients, or former heroin addicts dependent on methadone and participating in a naltrexone treatment programme; 89% were male.

INTERVENTION

Maintenance treatments on opiate dependent people after detoxification, comparing naltrexone with placebo, pharmacological or behavioural treatments.

MEASUREMENTS

The outcomes considered were successfully completed treatment, opioid use under treatment (re)-incarcerations during the study period, mean duration of treatment.

FINDINGS

The outcomes tended to be slightly although not significantly in favour of the naltrexone groups. Use of naltrexone in addition to behavioural treatment significantly decreased the probability of (re-)incarceration (OR=0.30; 95% CI 0.12, 0.76). The difficulties in producing a quantitative analysis were due mainly to the heterogeneity of the included studies.

CONCLUSIONS

From the available clinical trials performed up to this time, there is insufficient evidence to justify the use of naltrexone in maintenance treatment of opioid addicts.

History and current status of opioid maintenance treatments: blending conference session

Opiate addiction is a chronic, relapsing disorder. Left untreated, high morbidity and mortality rates are seen. Pharmacotherapies for this disorder using mu opiate agonists (methadone and levomethadyl acetate) and partial agonists have been developed in the last 40 years. Agonist pharmacotherapy with oral methadone for the treatment of opiate dependence was developed in clinical pharmacology studies at Rockefeller University by Dole, Nyswander, and Kreek. Further studies by this laboratory and others established that moderate to high dose treatment with methadone (80-120 mg) reduced or eliminated opiate use in outpatient settings with consequent reductions in morbidity and up to 4-fold reductions in mortality. Levomethadyl acetate (LAAM), a congener of methadone, is biotransformed to active metabolites responsible for its longer duration of action. The Federal Regulations regarding the dispensation of methadone and LAAM have recently been revised to facilitate the treatment of patients under a "medical maintenance" model. Future regulatory reform will likely involve the establishment of rules for "office based opioid treatment."

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.

Naltrexone maintenance treatment for opioid dependence

BACKGROUND

Despite widespread use of naltrexone maintenance in many countries for more than a decade, the evidence of its effects has not yet been systematically evaluated.

OBJECTIVES

To evaluate the effects of naltrexone maintenance treatment in preventing relapse in opioid addicts after detoxification.

SEARCH STRATEGY

We searched MEDLINE (1973-first year of naltrexone use in humans-July 2000), EMBASE (1974-July 2000), Cochrane Controlled Trials Register (Cochrane Library issue 2001.4) and handsearched the "Bolletino per le Farmacodipendenze e l'Alcolismo" (1978 to 1997) and reference lists of relevant articles. We contacted pharmaceutical producers of naltrexone, authors and other Cochrane review groups. Date of most recent searches: December 2001.

SELECTION CRITERIA

All controlled studies of naltrexone; treatment of heroin addicts after detoxification.

DATA COLLECTION AND ANALYSIS

Reviewers evaluated data independently and analysed outcome measures taking into consideration adherence to and success of the study intervention. Data were extracted and analysed stratifying for the three categories of study quality. Where possible, meta-analysis was performed.

MAIN RESULTS

Eleven studies met the criteria for inclusion in this review, even if not all of them were randomised. The methodological quality of the included studies varied, but was generally poor. Meta-analysis could be performed to a very low degree only, because the studies and their outcome measures were very heterogeneous. A statistically significant reduction of (re-)incarcerations was found for patients treated with naltrexone and behaviour therapy in respect to those treated with behaviour therapy only. The other outcomes considered in the meta-analysis did not yield any significant results. Final conclusions on whether naltrexone treatment may be considered effective in maintenance therapy cannot be drawn from the clinical trials available so far.

REVIEWER'S CONCLUSIONS

The available trials do not allow a final evaluation of naltrexone maintenance treatment yet. A trend in favour of treatment with naltrexone was observed for certain target groups (particularly people who are highly motivated), as has been previously described in the literature.

HIV/AIDS and drug abuse: epidemiology and prevention

In the United States, the AIDS epidemic is a dynamic process with increasing rates of AIDS reported among women, minority populations, heterosexual men, and users of drugs by routes other than injection. The 1993 CDC AIDS definition change has created some difficulties in interpreting trends in the United States. Drug use continues to represent a significant problem among HIV-infected persons. Several strategies have been advanced to decrease transmission of HIV among drug users, their sexual partners and children. However, more effective and comprehensive prevention and treatment strategies are needed.

Levo-Alpha Acetyl Methadol (LAAM). Its advantages and drawbacks

Levo-Alpha Acetyl Methadol, or LAAM, is a medication therapy for individuals addicted to opiates that provides an alternative to methadone. Because it is administered only three times a week and, therefore, requires fewer clinic trips, patient acceptance can be higher than with methadone. While blocking the effects of other opiates and preventing withdrawal, LAAM does not produce a subjective high. However, because most patients are not familiar with LAAM, they may be initially more anxious and need more counseling and support when receiving the medication than they would with the more familiar methadone medication. On balance, LAAM enables clinic administrators and counselors to offer an alternative medication to methadone that some clients prefer once they become adjusted to it because of LAAM's even, stable effect. Through hypothetical but true-to-life case studies of LAAM use, it is possible to gain a clearer understanding of the advantages and drawbacks of using LAAM.

Double blind: double talk or are there ways to do better research

In an attempt to counteract placebo effects, scientists studying the effectiveness of medication often use the 'double blind' trial. Unfortunately, in less than 5% of the studies reported in major medical and psychiatric journals was there a check to determine whether patients and observers were blind. Between 1972 and 1983 there was increasing reliance on active placebos which attempt to mimic the effects of the medication. It is unlikely however, that patients are not aware of significantly different physiologic changes within them resulting from the different chemicals. Whenever a physician informs a subject that they may be on placebo or active treatment medication, they will spend much time in trying to guess when they are taking which. In these situations Philip's paradox will apply. This states that the more potent a therapeutic variable the less likely its efficacy can be 'proven' in a double-blind study. One can only 'prove' that medication is no more effective than placebo. To have a truly blind procedure, the active placebo must have identical physiological effects to those of the medication being studied. We are now using the patient's and the observer's awareness of changes as useful information to obtain: a guess factor, the percentage of correct guesses whether the patient is on medication or placebo; a direction factor, whether the patient considers the change beneficial or detrimental; an attributional factor, whether the change is considered to result from medication or other intervening variables. This information is usually reliable and can be analyzed with the usual statistical procedures.

Chronic opiate use during methadone detoxification: effects of a dose increase treatment

The effects of administering high methadone doses during detoxification treatment were examined on illicit opiate use and treatment retention in chronic opiate supplementors. Twenty-six applicants to a 90-day outpatient detoxification program who delivered 50% or more opiate-positive urine samples during treatment weeks 2 and 3 were randomly assigned to receive a constant 30-mg dose through treatment week 10 or an increase to 60 mg in week 4 with gradual reduction to 30 mg by week 10. Dosage for both groups was reduced to 0 mg during weeks 11-13. Treatment retention was better for experimental (median = 86 days) than for control (median = 41 days) subjects, but the difference was not statistically significant. In the dose increase group, percent opiate-positive urines decreased from 80% to 62% during the first two weeks of dose increase (t = 2.39, P less than 0.05); opiate positive rates for the control group remained above 80%. A 20% between group difference in percent of opiate positive urine tests persisted through study week 10 in subjects (N = 5 control, 7 experimental) who remained in treatment this long. Although the blind dose increase did improve treatment outcome, we concluded that the magnitude of the effect in this population of chronic opiate supplementors was insufficient to judge the procedure clinically useful.

Naltrexone treatment of heroin addiction: one-year follow-up

Pre-treatment characteristics and post-treatment outcome measures were compared for 40 patients who began naltrexone maintenance and 77 who did not after a 6-month period of temporary maintenance on L-alpha-acetylmethadol (methadyl acetate LAAM). Patients who chose to begin naltrexone were younger, had fewer incarcerations and fewer months incarcerated prior to LAAM treatment, had fewer opiate-free months following previous treatments, and were more likely to be of Caucasian ethnicity. One year later, significantly more patients who had received any naltrexone than those who had not were no longer in any treatment program and were opiate-free. We found no significant correlations between total duration of naltrexone-treatment and post-treatment outcome variables such as heroin use, arrests, incarcerations or enrollment in a treatment program.