Opioid antagonists under heavy sedation or anaesthesia for opioid withdrawal.

backgroundWithdrawal (detoxification) is necessary prior to drug-free treatment. It may also represent the end point of long-term opioid replacement treatment such as methadone maintenance. The availability of managed withdrawal is essential to an effective treatment system.

objectivesTo assess the effectiveness of interventions involving the administration of opioid antagonists to induce opioid withdrawal with concomitant heavy sedation or anaesthesia. SEARCH STRATEGY: Multiple electronic databases (including MEDLINE, EMBASE, PsycLIT, Australian Medical Index, Cochrane Controlled Trials Register, and CINAHL) were systematically searched. Reference lists of retrieved studies, reviews and conference abstracts were handsearched. SELECTION CRITERIA: Randomised or quasi-randomised controlled trials that compared the administration of opioid antagonists under heavy sedation or anaesthesia with another form of treatment. DATA COLLECTION AND ANALYSIS: One reviewer assessed studies for inclusion and undertook data extraction. Inclusion decisions and the overall process were confirmed by consultation between all three reviewers. MAIN

resultsAs yet, no studies have been published comparing treatment regimes involving the administration of opioid antagonists under heavy sedation or anaesthesia with other approaches to detoxification. Treatment regimes for the studies considered for this review varied in the opioid antagonist used, the dose and mode of administration, the anaesthetic agent, duration of anaesthesia and adjunct medications employed. More detailed monitoring of withdrawal is required before any conclusions can be drawn as to what comprises a typical pattern of withdrawal and what factors might influence the pattern. There is only very limited information on referral to ongoing treatment, and relapse to opioid use. Together with the lack of adequate comparisons, this makes it impossible to draw any conclusions about the long-term effectiveness, or the cost-effectiveness, of withdrawal induced by opioid antagonists under heavy sedation or anaesthesia. REVIEWER'S

conclusionsConsiderably more research evidence will be needed before any conclusions can be drawn regarding the effectiveness of managing withdrawal by administration of opioid antagonists under heavy sedation or anaesthesia. The risk of vomiting during sedation, respiratory depression and cardiac irregularities point to the approach being limited to facilities equipped for intubation, assisted ventilation and a high level of monitoring, and with the capacity to respond to adverse events that might occur. The approach must be regarded as experimental with both risks and benefits remaining uncertain.