Three medications are currently available for adult patients with alcohol dependence:
Which medication to use will depend on clinical judgment and patient preference? Each has a different mechanism of action and some patients may respond better to one type of medication than another. A patient's willingness to abstain has important implications for the choice of medication. For example, a study of oral naltrexone demonstrated a modest reduction in the risk of heavy drinking in people with mild dependence that chose to cut down rather than abstain1.
Naltrexone works by blocking the euphoria associated with alcohol use. Its use is contraindicated in patients taking opiates. Oral naltrexone is associated with lower percentage drinking days, fewer drinks per drinking day and longer times to relapse2, 3. It is most effective in patients with strong cravings. Efficacy beyond 12 weeks has not been established. Although it is especially helpful for curbing consumption in patients who have drinking ‘slips’ it may also be considered in patients who are motivated, have intense cravings and are not using or going to be using opioids. It appears to be less effective in maintenance of abstinence as meta-analyses have shown variable results. Monitoring of liver enzymes may be required.
Acamprosate works by reducing chronic withdrawal symptoms. Acamprosate increases the proportion of dependent drinkers who maintain abstinence for several weeks to months, a result demonstrated in multiple European studies and confirmed by a meta-analysis of 17 clinical trials4. However, this has not been demonstrated in patients who have not undergone detoxification and not achieved alcohol abstinence prior to beginning treatment. Acamprosate should be initiated as soon as possible after detoxification and the recommended duration of treatment is one year. Acamprosate is approved for use in patients who are abstinent at the start of treatment. There is currently insufficient evidence to suggest that acamprosate has a therapeutic advantage over naltrexone.
Disulfiram requires total abstinence and counselling before initiation and should be used with caution. Disulfiram is contraindicated in patients who continue to drink because a disulfiram-alcohol reaction occurs with any alcohol intake.
Data on the effectiveness of disulfiram in alcohol use disorders is mixed. Disulfiram has been shown to have modest effects on maintaining abstinence from alcohol, particularly if it is administered under supervision. As it is most effective when given in a monitored fashion (such as in a clinic or by a spouse), the utility and effectiveness of disulfiram may be considered limited because compliance is generally poor when patients are given it to take at their own discretion5, 6.
Disulfiram may be considered for those patients that can achieve initial abstinence, are committed to maintaining abstinence, can understand the consequences of drinking alcohol while on disulfiram, and can receive adequate ongoing supervision. It may also be used episodically for high-risk situations, such as social occasions where alcohol is present. Daily uninterrupted disulfiram therapy should be continued until full patient recovery, which may require months to years.
The risk for relapse to alcohol dependence is very high in the first 6–12 months after initiating abstinence and gradually diminishes over several years. Therefore, a minimum initial period of six months of pharmacotherapy is recommended. Although optimal treatment duration has yet to be established, treatment can continue for one to two years if the patient responds to medication during this time when the risk of relapse is highest. After patients discontinue medications, they may need to be followed more closely and have pharmacotherapy reinstated if relapse occurs.
If there is no response to the first medication selected, you may wish to consider a second. This sequential approach appears to be common clinical practice, but currently there are no published studies examining its effectiveness. There is not enough evidence to recommend a specific ordering of medications.
There is no evidence that combining any of the medications to treat alcohol dependence improves outcomes over using any one medication alone.
As no single approach is universally successful or appealing to patients, offering the full range of effective treatments will maximize patient choice and outcomes. Medications for alcohol dependence, professional counselling and mutual help groups are all part of a comprehensive approach. These approaches share the same goal while addressing the neurobiological, psychological and social aspects of alcohol dependence. The medications are not prone to abuse, so they do not pose a conflict with other support strategies that emphasize abstinence. Using medications to treat patients does not interfere with counselling or other abstinence based programs such as Alcoholics Anonymous.
Almost all studies of medications for alcohol dependence have included some type of counselling, and it is recommended that all patients taking these medications receive at least brief medical counselling. In a recent large trial, the combination of oral naltrexone and brief medical counselling sessions delivered by a nurse or physician was effective without additional behavioural treatment by a specialist7. Patients were also encouraged to attend mutual support groups to increase social encouragement for abstinence.