In this guest post Clare Sharp, a PhD researcher at the University of Stirling, explores the implications of new research on the use of drugs used to support alcohol treatment.
A new review by researchers in France throws doubt on the efficacy of pharmacotherapy for controlled/reduced drinking in dependent drinkers.
Pharmacotherapy is just one of a wide range of possible treatments for alcohol dependence and not recommended for use without adjacent psychological support. Disulfiram, an aversive therapy, which causes nausea/vomiting when combined with alcohol, has been used since the 1940s to treat alcohol problems, in recent times under supervised consumption.
Since then increasing research and knowledge about how processes in the brain react to alcohol has led to the development of a new set of alcohol dependence drugs including nalmefene and naltrexone, which are thought to work on the brain to reduce the urge to drink, whilst acamprosate is thought to help stabilize chemical imbalances in the brain which occur during alcohol withdrawal. Whilst most alcohol dependence drugs have been licensed for maintaining abstinence in those who have successfully withdrawn from alcohol, nalmefene is the only drug to be licensed for the reduction of alcohol consumption in patients who intend to continue to drink. However, drugs such as acamprosate and naltrexone have also been used ‘off-label’ for this purpose.
Whether the goal of pharmacotherapy should be aimed towards one of maintaining abstinence or whether it should also be used to control drinking is the subject of a wider debate. Nalmefene has been viewed as controversial, hailed as a ‘paradigm shift’ by those in support but as an example of ‘bad medicine’ by others. Although it was approved by NICE for use in the UK in 2014, critics of the drug point to concerns about its evidence base. Reviews previously published by Palpacuer and colleagues in 2015 and by researchers led by the University of Stirling in 2016 highlighted issues with the clinical trials evidence including: high patient drop-out rates; unplanned analyses; and minimal observed effec
The latest review raises similar issues but covers five drugs for alcohol dependence (nalmefene, naltrexone, acamprosate, topiramate and baclofen) in 32 studies published between 1994 and 2015. Of these drugs, topiramate and baclofen have not been officially approved for treating alcohol dependence but have been studied in relation to their efficacy in treating this patient group. It looked at whether these drugs can reduce total alcohol consumption in adults with alcohol dependence who continue to drink alcohol. The authors concluded that there is insufficient evidence to say that these drugs can successfully reduce drinking, and report similar issues to those raised for nalmefene, including:
- that no comparison was made with any other drug treatment in any of the 32 studies, meaning that little is known about the relative effectiveness of one drug compared with another;
- the high level of dropout in the majority of studies, leading to incomplete data and possible attrition bias;
- that any effect on alcohol consumption resulting from the drug treatment was small;
- that none of the studies could reliably demonstrate any harm reduction from using these drugs as they did not consider any health outcomes, only alcohol consumption outcomes;
- and that a lack of protocol registration details for just over half of the 32 studies meant that pre-specified outcomes for these studies could not be checked to ensure that they were all reported in the study results.
This review raises issues for practitioners, policy makers and researchers. It suggests that there is insufficient evidence for a range of alcohol dependence drugs which have been approved for use in the UK. Although this specific review relates only to efficacy in reducing alcohol consumption rather than maintaining abstinence, other reviews of the benefits of pharmacotherapy for alcohol dependence have raised similar questions about efficacy. The uncertainty around the evidence base for these drugs will add to the challenges faced by practitioners in making evidence-based decisions about appropriate treatment options for patients with alcohol dependence, especially those at the milder end of the alcohol dependence spectrum, whose treatment goal may be one of moderation rather than abstinence. The authors of this latest review have called for changes in the way that trials are conducted in order to improve the quality of the evidence base, and a need for consensus on how to take this forward.
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