March 31, 2000 (Atlanta) -- For drinkers who want to quit, there's a new drug called acamprosate that curbs the urge to take that first drink -- the one that so often leads to full relapse. What's more, it seems to be safe for the vast majority of alcoholics, including those with liver problems and other addictive disorders.
Though still awaiting FDA approval, the drug has shown promising results in several European studies and in a large clinical trial that just concluded here in the U.S.
Barbara Mason, PhD, the trial's principal researcher, describes acamprosate as an exciting, safe option. "It's not magic that will get an unmotivated, drinking person to be transformed," she tells WebMD. "It isn't Tinkerbell's wand. But in the motivated patient, it does give added benefit beyond the behavioral therapy which has traditionally been available." At the University of Miami, Mason is professor of psychiatry and behavioral sciences and director of the division of substance abuse.
For the six-month trial, Mason enrolled a group of patients that mirrored the alcoholic population -- very diverse in terms of ethnicity, age, severity of disorder, liver problems, use of other addictive substances, and geographic location. Most had been drinking since age 15, with symptoms of drinking problems (missing work, etc.) first showing as they got closer to age 30. One-third were women, also mirroring alcoholism trends in the general population.
The trial was done in medical centers and community-based treatment settings in 21 cities across the U.S., with about 600 men and women participating. The participants received either 2 g of acamprosate or a placebo. A small number received an exploratory 3 g of acamprosate. Blood tests were used to monitor the volunteers' compliance in taking the drug.
Although she is still putting the data together, Mason says that preliminary results are similar to what the European trials showed -- that with acamprosate, abstinence from alcohol increased by 10-25%. The 3 g dose was also well tolerated and showed linear dose response, meaning the higher the dosage, the better the results, says Mason. "But again, that's exploratory," she says.
A European trial published in The Lancet last May involved almost 450 people with chronic or episodic alcohol dependency. By the end of the trial, 41 patients taking acamprosate remained abstinent, vs. 18 receiving a placebo. Those in the acamprosate group who had relapses remained abstinent longer than their counterparts in the placebo group.
Acamprosate is the third medication aimed at helping alcoholics curb their habit. Antabuse (disulfiram), which has been available for about 40 years, works by blocking alcohol metabolism. It therefore causes a very toxic reaction when an alcoholic takes a drink.
Developed more recently, ReVia (naltrexone) is an opioid blocker that binds with the pleasure receptors in the brain so alcohol doesn't overstimulate them. "Naltrexone blocks the rewarding effects of alcohol," Mason says.
Acamprosate works with an entirely different system in the brain, the glutamate system, which becomes hyperactive during alcohol withdrawal and can remain hyperactive for up to a year of abstinence, says Mason. Acamprosate appears to normalize the activity of that system.
The drug also seems to be tolerated better by more people, she adds. Where naltrexone may exacerbate an existing liver problem, acamprosate is absorbed in the gastrointestinal tract and reaches an effective level within one week. Also, acamprosate can be safely taken by people with other addictions, such as heroin addicts. "So it's useful with a broader range of patients, both in terms of medical problems and polysubstance abuse," says Mason.
" [Mason's] reputation is top-notch in the field of alcohol research," says Joy Schmitz, PhD, an associate professor of psychiatry and behavioral sciences at the University of Texas Health Sciences Center in Houston. Schmitz is the lead researcher in a four-year study of naltrexone and the nicotine patch in treating alcoholism and smoking, funded by the National Institute on Alcohol Abuse and Alcoholism.
"The more medications we have available ? each of them targeting it from a different angle, it can only help, because no one alcoholic is like the next one," Schmitz tells WebMD. "Some respond more to one type of approach. Down the road, it would be nice to try to better match what kind of alcohol-dependent person benefits most from what treatment."
The trial was funded by Lipha Pharmaceuticals, the drug's developer.
- An experimental drug called acamprosate has been shown to curb the urge to drink alcohol and increases abstinence among alcoholics by 10-25%.
- The drug is safe for patients with liver problems or those also being treated for other addictions, such as heroin.
- During alcohol withdrawal, the glutamate system of the brain remains hyperactive for up to a year of abstinence, but acamprosate works to normalize that system.