A double-blind, randomized, parallel group study to compare the efficacy, safety and tolerability of slow-release oral morphine versus methadone in opioid-dependent in-patients willing to undergo detoxification

Relative effectiveness of medications for opioid-related disorders: A systematic review and network meta-analysis of randomized controlled trials

INTRODUCTION

Several pharmacotherapeutic interventions are available for maintenance treatment for opioid-related disorders. However, previous meta-analyses have been limited to pairwise comparisons of these interventions, and their efficacy relative to all others remains unclear. Our objective was to unify findings from different healthcare practices and generate evidence to strengthen clinical treatment protocols for the most widely prescribed medications for opioid-use disorders.

METHODS

We searched Medline, EMBASE, PsycINFO, CENTRAL, and ClinicalTrials.gov for all relevant randomized controlled trials (RCT) from database inception to February 12, 2022. Primary outcome was treatment retention, and secondary outcome was opioid use measured by urinalysis. We calculated risk ratios (RR) and 95% credible interval (CrI) using Bayesian network meta-analysis (NMA) for available evidence. We assessed the credibility of the NMA using the Confidence in Network Meta-Analysis tool.

RESULTS

Seventy-nine RCTs met the inclusion criteria. Due to heterogeneity in measuring opioid use and reporting format between studies, we conducted NMA only for treatment retention. Methadone was the highest ranked intervention (Surface Under the Cumulative Ranking [SUCRA] = 0.901) in the network with control being the lowest (SUCRA = 0.000). Methadone was superior to buprenorphine for treatment retention (RR = 1.22; 95% CrI = 1.06-1.40) and buprenorphine superior to naltrexone (RR = 1.39; 95% CrI = 1.10-1.80). However, due to a limited number of high-quality trials, confidence in the network estimates of other treatment pairs involving naltrexone and slow-release oral morphine (SROM) remains low.

CONCLUSION

All treatments had higher retention than the non-pharmacotherapeutic control group. However, additional high-quality RCTs are needed to estimate more accurately the extent of efficacy of naltrexone and SROM relative to other medications. For pharmacotherapies with established efficacy profiles, assessment of their long-term comparative effectiveness may be warranted.

TRIAL REGISTRATION

This systematic review has been registered with PROSPERO (https://www.crd.york.ac.uk/prospero) (identifier CRD42021256212).

Treatment-refractory substance use disorder: Focus on alcohol, opioids, and cocaine

Substance use disorders are common, but only a small minority of patients receive adequate treatment. Although psychosocial therapies are effective, relapse is common. This review focusses on novel pharmacological and other treatments for patients with alcohol, opioid, or cocaine use disorders who do not respond to conventional treatments. Disulfiram, acamprosate, and the opioid antagonist naltrexone have been approved for the treatment of alcoholism. A novel, "as needed" approach is the use of the mu-opioid antagonist and partial kappa agonist nalmefene to reduce alcohol consumption. Other novel pharmacological approaches include the GABA-B receptor agonist baclofen, anticonvulsants such as topiramate and gabapentin, the partial nicotine receptor agonist varenicline, and other drugs. For opioid dependence, opioid agonist therapy with methadone or buprenorphine is the first-line treatment option. Other options include oral or depot naltrexone, morphine sulfate, depot or implant formulations, and heroin (diacetylmorphine) in treatment-refractory patients. To date, no pharmacological treatment has been approved for cocaine addiction; however, 3 potential pharmacological treatments are being studied, disulfiram, methylphenidate, and modafinil. Pharmacogenetic approaches may help to optimize treatment response in otherwise treatment-refractory patients and to identify which patients are more likely to respond to treatment, and neuromodulation techniques such as repeated transcranial magnetic stimulation and deep brain stimulation also may play a role in the treatment of substance use disorders. Although no magic bullet is in sight for treatment-refractory patients, some novel medications and brain stimulation techniques have the potential to enrich treatment options at least for some patients.

Pharmacological strategies for detoxification

Detoxification refers to the safe discontinuation from a substance of dependence and is distinct from relapse prevention. Detoxification usually takes between a few days and a few weeks to complete, depending on the substance being misused, the severity of dependence and the support available to the user. Psychosocial therapies alongside pharmacological treatments are essential to improve outcome. The dependencies considered in this overview are detoxification from opioids (with methadone, buprenorphine, α2-adrenoceptor agonists and adjunct medications), alcohol (with benzodiazepines, anti-glutamatergics and γ-aminobutyric acid (GABA)-ergic drugs), stimulants and cannabis (with no clear recommended pharmacological treatments), benzodiazepines (with dose tapering) and nicotine (with nicotine replacement therapy, antidepressants and partial agonists). Evidence is limited by a lack of controlled trials robust enough for review bodies, and more research is required into optimal treatment doses and regimes, alone and in combination.

Rapid opiate detoxification and antagonist induction under general anaesthesia or intravenous sedation is humane, sometimes essential and should always be an option. Three illustrative case reports involving diabetes and epilepsy and a review of the literature

When abstinence is an appropriate goal, controlled studies and systematic reviews confirm that rapid, antagonist-precipitated opiate withdrawal procedures are the most effective and cost effective methods of initiating abstinence, and naltrexone (NTX) maintenance. While 'rapid' withdrawal, better conceptualised as Rapid Antagonist Induction (RAI), can often be humanely achieved with modest sedation levels, we present three case histories to support our argument that for some patients, general anaesthesia (GA), or techniques of intravenous sedation (IVS) that approach GA, are essential for safety and success. This includes patients with intercurrent disease (e.g. epilepsy or insulin-dependent diabetes) but also those with severe withdrawal phobia after previous distressing experiences. We discuss the history of the procedure. The dangers of RAI under GA or IVS in experienced hands have been exaggerated and the appropriate expertise should be more easily available. Patients and clinicians readily accept risks of major surgery for the excessive intake of food that causes most obesity. Similar risk-acceptance exists in cosmetic surgery and obstetrics. The increasing use and effectiveness of long-acting implants or depot-injections of NTX for relapse-prevention have largely solved compliance problems that undermined the potential of oral NTX. Their ability to prevent opiate overdose in abstinent, non-tolerant patients also strengthens arguments both for offering RAI as a therapeutic option and for reducing psychological, professional and practical barriers to using it.

Slow-release oral morphine as maintenance therapy for opioid dependence

BACKGROUND

Opioid substitution treatments are effective in retaining people in treatment and suppressing heroin use. An open question remains whether slow-release oral morphine (SROM) could represent a possible alternative for opioid-dependent people who respond poorly to other available maintenance treatments.

OBJECTIVES

To evaluate the efficacy of SROM as an alternative maintenance pharmacotherapy for the treatment of opioid dependence.

SEARCH METHODS

We searched Cochrane Drugs and Alcohol Group's Register of Trials, Cochrane Central Register of Controlled Trials (CENTRAL - The Cochrane Library Issue 3, 2013), MEDLINE (January 1966 to April 2013), EMBASE (January 1980 to April 2013) and reference lists of articles.

SELECTION CRITERIA

Randomised controlled trials (RCTs) and quasi-randomised trials assessing efficacy of SROM compared with other maintenance treatment or no treatment.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected articles for inclusion, extracted data and assessed risk of bias of included studies.

MAIN RESULTS

Three studies with 195 participants were included in the review. Two were cross-over trials and one was a parallel group RCT. The retention in treatment appeared superior to 80% in all the three studies (without significant difference with controls). Nevertheless, it has to be underlined that the studies had different durations. One lasted six months, and the other two lasted six and seven weeks. The use of opioids during SROM provision varied from lower to non-statistically or clinically different from comparison interventions, whereas there were no differences as far as the use of other substances was concerned.SROM seemed to be equal to comparison interventions for severity of dependence, or mental health/social functioning, but there was a trend for less severe opiate withdrawal symptoms in comparison with methadone (withdrawal score 2.2 vs. 4.8, P value = 0.06). Morphine was generally well tolerated and was preferred by a proportion of participants (seven of nine people in one study). Morphine appeared to reduce cravings, depressive symptoms (measured using the Beck Depression Inventory; P value < 0.001), physical complaints (measured using the Beschwerde-Liste (BL); P value < 0.001) and anxiety symptoms (P value = 0.008). Quality of life in people treated with SROM resulted in no significant difference or a worst outcome than in those taking methadone and buprenorphine. Other social functioning measures, such as finances, family and overall satisfaction, scored better in people maintained with the comparison substances than in those maintained with SROM. In particular, people taking methadone showed more favourable values for leisure time (5.4 vs. 3.7, P value < 0.001), housing (6.1 vs. 4.7, P value < 0.023), partnerships (5.7 vs. 4.2, P value = 0.034), friend and acquaintances (5.6 vs. 4.4, P value = 0.003), mental health (5.0 vs. 3.4, P value = 0.002) and self esteem (8.2 vs. 5.7, P value = 0.002) compared to people taking SROM; while people taking buprenorphine obtained better scores for physical health.Medical adverse events were consistently higher in people in SROM than in the comparison groups. None of the studies included people with a documented poor response to other maintenance treatment.

AUTHORS' CONCLUSIONS

The present review did not identify sufficient evidence to assess the effectiveness of SROM for opioid maintenance because only three studies meeting our inclusion criteria have been identified. Two studies suggested a possible reduction of opioid use in people taking SROM. In another study, the use of SROM was associated with fewer depressive symptoms. Retention in treatment was not significantly different among compared interventions while the adverse effects were more frequent with the people given SROM.

Methadone at tapered doses for the management of opioid withdrawal

BACKGROUND

The evidence of tapered methadone's efficacy in managing opioid withdrawal has been systematically evaluated in the previous version of this review that needs to be updated

OBJECTIVES

To evaluate the effectiveness of tapered methadone compared with other detoxification treatments and placebo in managing opioid withdrawal on completion of detoxification and relapse rate.

SEARCH METHODS

We searched: Cochrane Central Register of Controlled Trials (The Cochrane Library 2012, Issue 4), PubMed (January 1966 to May 2012), EMBASE (January 1988 to May 2012), CINAHL (2003- December 2007), PsycINFO (January 1985 to December 2004), reference lists of articles.

SELECTION CRITERIA

All randomised controlled trials that focused on the use of tapered methadone versus all other pharmacological detoxification treatments or placebo for the treatment of opiate withdrawal.

DATA COLLECTION AND ANALYSIS

Two review authors assessed the included studies. Any doubts about how to rate the studies were resolved by discussion with a third review author. Study quality was assessed according to the criteria indicated in the Cochrane Handbook for Systematic Reviews of Interventions.

MAIN RESULTS

Twenty-three trials involving 2467 people were included. Comparing methadone versus any other pharmacological treatment, we observed no clinical difference between the two treatments in terms of completion of treatment, 16 studies 1381 participants, risk ratio (RR) 1.08 (95% confidence interval (CI) 0.97 to 1.21); number of participants abstinent at follow-up, three studies, 386 participants RR 0.98 (95% CI 0.70 to 1.37); degree of discomfort for withdrawal symptoms and adverse events, although it was impossible to pool data for the last two outcomes. These results were confirmed also when we considered the single comparisons: methadone with: adrenergic agonists (11 studies), other opioid agonists (eight studies), anxiolytic (two studies), paiduyangsheng (one study). Comparing methadone with placebo (two studies) more severe withdrawal and more drop-outs were found in the placebo group. The results indicate that the medications used in the included studies are similar in terms of overall effectiveness, although symptoms experienced by participants differed according to the medication used and the program adopted.

AUTHORS' CONCLUSIONS

Data from literature are hardly comparable; programs vary widely with regard to the assessment of outcome measures, impairing the application of meta-analysis. The studies included in this review confirm that slow tapering with temporary substitution of long- acting opioids, can reduce withdrawal severity. Nevertheless, the majority of patients relapsed to heroin use.

Newer approaches to opioid detoxification

Opioid use disorders present with distressing withdrawal symptoms at the time of detoxification. The pharmacological agents and methods currently in use for detoxification mainly include buprenorphine, methadone, and clonidine. Many other pharmacological agents have been tried for opioid detoxification. This review takes a look at the newer pharmacological options, both opioid agonists and non-agonist medications that have been utilized for detoxification. Peer reviewed articles were identified using PubMed and PsychInfo databases. The keywords included for the search were a combination of 'opioid' and 'detoxification' and their synonyms. All the articles published in the last 10 years were screened for. Relevant data was extracted from identified studies. Many newer pharmacological agents have been tried in detoxification of opioids. However, the quest for a safe, efficacious, cost-effective pharmacological option which requires minimal monitoring still continues. The role of non-pharmacological measures and alternative medicine needs further evaluation.

BAP updated guidelines: evidence-based guidelines for the pharmacological management of substance abuse, harmful use, addiction and comorbidity: recommendations from BAP

The British Association for Psychopharmacology guidelines for the treatment of substance abuse, harmful use, addiction and comorbidity with psychiatric disorders primarily focus on their pharmacological management. They are based explicitly on the available evidence and presented as recommendations to aid clinical decision making for practitioners alongside a detailed review of the evidence. A consensus meeting, involving experts in the treatment of these disorders, reviewed key areas and considered the strength of the evidence and clinical implications. The guidelines were drawn up after feedback from participants. The guidelines primarily cover the pharmacological management of withdrawal, short- and long-term substitution, maintenance of abstinence and prevention of complications, where appropriate, for substance abuse or harmful use or addiction as well management in pregnancy, comorbidity with psychiatric disorders and in younger and older people.

Slow-release oral morphine for opioid maintenance treatment: a systematic review

This review article summarizes the results of all available clinical trials considering the use of slow-release oral morphine (SROM) for opioid maintenance treatment (OMT). All studies published up to October 2010 and assessing SROM for OMT in adult patients are included. Three independent reviewers assessed the selected articles using a standardized checklist. Study design, study length and number of subjects included were recorded. Data about retention rate (proportion of participants remaining under maintenance treatment at the end of the study), quality of life, withdrawal symptoms, craving, additional drug consumption, driving capacity and adverse events were collected. We identified 13 articles corresponding to nine clinical trials considering the use of SROM for OMT. Among them, only one was a randomized trial and one was a controlled not randomized trial. All other studies were uncontrolled. Retention rates were good (from 80.6 to 95%) with SROM maintenance, but similar retention rates were obtained with methadone. Most of the studies showed that quality of life, withdrawal symptoms, craving and additional drug consumption improved with SROM. However, there was no comparison with other maintenance drugs. As most of the studies assessing SROM efficacy were uncontrolled, there is no definite evidence that SROM is an effective alternative to methadone for OMT.

The World Federation of Societies of Biological Psychiatry (WFSBP) guidelines for the biological treatment of substance use and related disorders. Part 2: Opioid dependence

OBJECTIVES

To develop evidence-based practice guidelines for the pharmacological treatment of opioid abuse and dependence.

METHODS

An international task force of the World Federation of Societies of Biological Psychiatry (WFSBP) developed these practice guidelines after a systematic review of the available evidence pertaining to the treatment of opioid dependence. On the basis of the evidence, the Task Force reached a consensus on practice recommendations, which are intended to be clinically and scientifically meaningful for physicians who treat adults with opioid dependence. The data used to develop these guidelines were extracted primarily from national treatment guidelines for opioid use disorders, as well as from meta-analyses, reviews, and publications of randomized clinical trials on the efficacy of pharmacological and other biological treatments for these disorders. Publications were identified by searching the MEDLINE database and the Cochrane Library. The literature was evaluated with respect to the strength of evidence for efficacy, which was categorized into one of six levels (A-F).

RESULTS

There is an excellent evidence base supporting the efficacy of methadone and buprenorphine or the combination of buprenorphine and naloxone for the treatment of opioid withdrawal, with clonidine and lofexidine as secondary or adjunctive medications. Opioid maintenance with methadone and buprenorphine is the best-studied and most effective treatment for opioid dependence, with heroin and naltrexone as second-line medications.

CONCLUSIONS

There is enough high quality data to formulate evidence-based guidelines for the treatment of opioid abuse and dependence. This task force report provides evidence for the efficacy of a number of medications to treat opioid abuse and dependence, particularly the opioid agonists methadone or buprenorphine. These medications have great relevance for clinical practice.

Mortality and employment after in-patient opiate detoxification

AIM

We considered that completed opiate detoxification resulted in increased life expectancy and earning capacity as compared to non-completed detoxification.

METHODS

The cohort study sample included pure opioid or poly-substance addicts admitted for voluntary in-patient detoxification between 1997 and 2004. Of 404 patients, 58.7% completed the detoxification program and 41.3% did not. The Austrian Social Security Institution supplied data on survival and employment records for every single day in the individual observation period between discharge and December 2007. Statistical analyses included the calculation of standardized mortality rates for the follow-up period of up to 11 years.

RESULTS

The standardized mortality ratios (SMRs) were between 13.5 and 17.9 during the first five years after discharge, thereafter they fell clearly with time. Mortality did not differ statistically significantly between completers and non-completers. The median employment rate was insignificantly higher in completers (12.0%) than in non-completers (5.5%). The odds for being employed were higher in pure opioid addicts than in poly-substance addicts (p=0.003).

CONCLUSIONS

The assumption that completers of detoxification treatment have a better outcome than non-completers has not been confirmed. The decrease in mortality with time elapsed since detoxification is interesting. Pure opioid addicts had better employment prospects than poly-substance addicts.