A systematic review of the evidence available on medications for alcohol use disorders from the University of North Carolina at Chapel Hill finds that they are effective for maintaining abstinence or reducing drinking, despite not being widely prescribed among people with these disorders.
Less than one third of people with an alcohol use disorder receive any treatment and less than 10% receive medications that could help reduce their alcohol consumption.
The University of North Carolina at Chapel Hill (UNC) team conducted a systematic review of the evidence available on the use of drugs to treat alcohol disorders, including 122 randomized controlled trials and one cohort study. The UNC team's findings are published in JAMA.
"There are many studies that have tried to show whether certain medications can help with alcohol use disorders, but it is a lot of information to digest and many providers do not know what works or doesn't work," says Daniel Jonas, lead author of the study and professor in the department of medicine and the Cecil G. Sheps Center for Health Services Research.
"When you synthesize all the evidence," he says, "it shows pretty clearly that some medications do work."
Review finds strong evidence to support acamprosate and oral naltrexone
The systematic review found two drugs that have strong evidence to support their use in reducing alcohol consumption. Patients using these medications - acamprosate (brand name Campral) and oral naltrexone (brand name Revia) - were shown to be less likely to return to drinking.
Acamprosate was approved by the Food and Drug Administration (FDA) in 2004, making it the first new treatment for alcohol use disorders in a decade.
Previously, alcohol abstinence medications worked by inducing vomiting if the patient consumes alcohol, or by blocking the intoxicating "high" associated with alcohol. Acamprosate works instead by interacting with neurotransmitters, theoretically restoring a balance between neuronal excitation and inhibition that is distorted by chronic alcohol exposure.
The review found that patients using acamprosate or oral naltrexone were shown to be less likely to return to drinking.
When the drug was launched, however, acamprosate's manufacturer - Forest Laboratories - admitted that the mechanism it uses to maintain alcohol abstinence was not completely understood.
A significant percentage of people with alcohol use disorders experience opioid stimulation when they drink alcohol, which produces euphoria.
Naltrexone works by acting on the opioid receptors and reducing the euphoric sensation. Naltrexone cannot cure alcohol use disorders, but it is shown to make patients more receptive to treatment, and so works well in combination with 12-step programs or behavior therapy.
The team also found that two medications not currently approved by the FDA for treating alcohol use disorders - topiramate and nalmefene - had moderate evidence showing improved drinking outcomes.
"The health implications of preventing return to drinking and reducing alcohol consumption are substantial," says Prof. Jonas.
He goes on to explain that modeling studies assessing the benefits of preventing people with alcohol use disorders from returning to drinking have demonstrated that alcohol-attributable mortality, costs from health care, arrests and vehicle accidents would all be reduced.
James Garbutt, professor of psychiatry and scientist at UNC's Bowles Center for Alcohol Studies and senior author on the paper, concludes:
"This work expands upon the growing evidence that medications can play a valuable role in the treatment of alcohol use disorders. We are hopeful that this information will encourage clinicians to strongly consider these medications and that individuals will gain awareness that there are medications that can help them to stop or significantly reduce their alcohol use."