The anticonvulsant gabapentin, a widely prescribed anticonvulsant used to treat epilepsy and neuropathic pain, is showing promise in the treatment of alcohol dependence, new research suggests.

Results from a 12-week, randomized, placebo-controlled trial show that participants taking 1800 mg of gabapentin were twice as likely to refrain from heavy drinking and 4 times as likely to stop drinking altogether compared with participants taking placebo.

“Gabapentin’s effect on drinking outcomes is at least as large or greater than those of existing FDA-approved treatments,” lead researcher Barbara Mason, PhD, Scripps Research Institute, La Jolla, California, said in a statement.

The study was published online November 4 in JAMA Internal Medicine.

Filling a Treatment Gap

According to investigators, gabapentin has the potential to fill a large gap in the treatment of alcohol dependence. They note that of the estimated 8.5 million alcohol-dependent Americans, statistics show that only 720,000 prescriptions were filled for US Food and Drug Administration (FDA)–approved medications for alcohol dependence in 2007, most of them prescribed by psychiatrists.

Previous studies of gabapentin for alcohol-dependent persons have suggested that the drug may be safe and effective, but conclusive results have been hampered by small sample size and methodologic or dosing issues.

To provide a more definitive evaluation of the drug for alcohol dependence, the researchers conducted a 12-week, double-blind, placebo-controlled, randomized, dose-ranging trial of 150 adults with current alcohol dependence who were attending a single outpatient center.

Participants were randomly assigned to receive 900 mg/day, 1800 mg/day, or placebo. All patients received concomitant counseling.

The study’s primary outcomes included sustained abstinence and no heavy drinking, and decreases in alcohol-related insomnia, dysphoria, and craving in a dose-dependent manner.

Results showed that gabapentin significantly improved the rates of abstinence and no heavy drinking with rates of 4.1% (95% confidence interval [CI], 1.1% – 13.7%) in the placebo group, 11.1% (85% CI, 5.2% – 22.2%) in the 900-mg group, and 17.0% (95% CI, 8.9% – 30.1%) in the 1800-mg group.

Further, the investigators report that the no-heavy-drinking rate was 22.5% (95% CI, 13.6% – 37.2%) in the placebo group, 29.6% (95% CI, 19.1% – 42.8%) in the 900-mg group, and 44.7% (95% CI, 31.4% – 58.8%) in the 1800-mg group.

In addition, the results showed that the drug significantly reduced cravings, depression, and sleeplessness. The researchers report that gabapentin had a favorable safety profile with no reports of serious adverse events.

According to Dr. Mason, gabapentin offers several potential advantages over the 3 other FDA-approved medications for alcohol dependence. It is “the only medication shown to improve sleep and mood in people who are quitting or reducing their drinking, and it’s already widely used in primary care ― that’s an appealing combination,” she said.

Broader Access to Treatment

In an accompanying editorial,Edward V. Nunes, MD, writes that the finding that gabapentin prevents relapse in alcohol-dependent patients is “an important development.”

“This well-designed and well-powered trial replicates the positive findings of several previous smaller trials,” Dr. Nunes writes.

He notes that a large proportion of alcohol-dependent patients presenting to family physicians fall into the mild to moderate range of alcohol dependence, which further suggests “the strong potential for gabapentin in the treatment of alcohol dependence in primary care.”

Acting director of the National Institute on Alcohol Abuse and Alcoholism, Kenneth R. Warren, PhD, said, “Gabapentin adds to the list of existing medications that have shown promise in treating alcohol dependence. We will continue to pursue research to expand the menu of treatment options available for alcoholism in the hopes of reaching more people.”