In Norway we offer opioid maintenance treatment with methadone or buprenorphine for people with opioid dependence. For most people who use methadone or buprenorphine the maintenance treatment has a lifelong perspective. We summarized the research on the effect of tapering the dosage of methadone or buprenorphine compared with continued opioid assisted maintenance treatment.
We found only one randomized controlled trial (published in 2015) that evaluated the effect of tapering from methadone. The study was set in the USA and included 223 people who was sentenced to serve a relatively short prison sentence.
The study we found had included too few people. It had high risk of bias due to lack of blinding. We cannot say anything for certain what the effect of tapering methadone is on the use of methadone maintenance treatment, illicit drugs, crime, adverse events such as hospitalization, disease and drug overdose, and mortality. The study did not measure outcomes such as adverse events, user satisfaction or work participation.
The Norwegian Directorate of Health has commissioned a systematic review of the effect of tapering methadone or buprenorphine compared with opioid maintenance treatment as usual for patients with opioid dependence. The results from this report may contribute to updating the guidelines for opioid maintenance treatment.
In Norway we offer opioid maintenance treatment for individuals with opioid dependence. For many patients who use methadone or buprenorphine the substitution treatment has a lifelong perspective. Today's policy is cautious when it comes to recommending dose reduction of methadone or buprenorphine.
We developed a systematic review to answer the following questions: For people with opioid dependence, what is the effect of tapering the dose of methadone or buprenorphine compared with treatment as usual, without tapering, on the following outcomes; completion of maintenance treatment, side effects, use of illicit drugs, disease, mortality, crime and satisfaction with treatment?
We searched for relevant studies in nine databases in October 2016. Inclusion criteria were:
Population: Persons with opioid dependence (illicit drugs such as heroin, morphine) treated with substitution drugs such methadone or buprenorphine.
Intervention: Tapering methadone or buprenorphine.
Comparison: No dose reduction, usual opioid assisted rehabilitation with methadone or buprenorphine.
Outcome: Continued maintenance treatment, side effects, use of illicit drugs, disease, mortality, crime, satisfaction with treatment and participation in work.
We searched for studies with the following design: Systematic reviews with moderate or high methodological quality published after 2005, randomized controlled trials, quasi-controlled trials, prospective controlled cohort studies, controlled before and after studies, and interrupted time series.
We used our handbook "How we summarize research" when we did this systematic review. Two people independently read titles and abstracts. Articles that seemed potentially relevant were obtained in full text and assessed against the inclusion criteria described above. One person extracted data from the included study and data extraction was checked by another person. We assessed the risk of bias in the study and used the Grading of Recommendations Assessment, Development and Evaluation (GRADE) to assess the trust of documentation.
We identified 397 references. Of these, 28 studies were reviewed in full text and one study was included. The study, which was from the US, included 223 people who were sentenced to up to six months imprisonment. Participants were predominantly white men with several years of heroin addiction and they had been many years in methadone maintenance treatment.
Participants were randomly assigned to a group that received treatment with methadone and another group who was tapered down with three to five milligram methadone daily.
Of those who received involuntary reduction of the methadone dose there were fewer people who sought methadone treatment within one month after release from serving a prison sentence with relative risk of 0.73 (95% confidence interval 0.64 - 0.82), more people experienced adverse events (such as hospitalization, visits to emergency services or drug overdose) with relative risk of 2.14 (confidence interval from 1.14 to 4.00). There was not a significant difference between the two groups in number of persons ending methadone with a confidence interval from 0.73 to 4.13, the use of illicit drugs, confidence interval from 0.99 to 1.43 and for crime measured with a confidence interval from 0.36 to 1.95. Regarding mortality, the data was uncertain with relative risks of 0.35 and a very wide confidence interval from 0.01 to 8.46. We have very low confidence in the available research findings. The study we found had not measured side effects, satisfaction with care or work.
We cannot draw any firm conclusions based on findings from just one small study.
The study we found evaluated the effects of a gradual reduction of the methadone dose for people who were sentenced to serve a prison sentence. They were randomly allocated to a gradual reduction of methadone or to be continued with methadone treatment. That means we cannot say with certainty whether the results can be relevant to people with a strong motivation for tapering.
We found one RCT with 223 participants. We are uncertain about the effectiveness of tapering compared to usual opioid assisted treatment with methadone on continued methadone maintenance, use of illicit drugs, disease, mortality and crime. We have no data to say whether tapering is more or less effective compared to usual opioid assisted treatment with methadone on the outcomes side effects, satisfaction with treatment and work.