Nausea Drug Shows Promise Against Opioid Addiction

WEDNESDAY, Feb. 18, 2009 (HealthDay News) -- A drug currently used to treat nausea can prevent symptoms of withdrawal from illegal and prescription opioid drugs such as heroin, morphine and codeine, a new study shows.

The Stanford University scientists behind the research added it can do so without some of the serious side effects caused by existing treatments for addiction to these drugs.

Initial tests in mice showed that the drug ondansetron (Zofran) blocks certain 5-HT3 receptors involved in withdrawal symptoms, the researchers said. They then tested it in eight healthy, non-opioid-dependent volunteers who were given two doses of morphine, once without ondansetron and one with it, and found ondansetron reduced withdrawal symptoms in humans.

The study appears in the Feb. 17 online issue of the Journal of Pharmacogenetics and Genomics.

"Opioid abuse is rising at a faster rate than any other type of illicit drug use, yet only about a quarter of those dependent on opioids seek treatment. One barrier to treatment is that when you abruptly stop taking the drugs, there is a constellation of symptoms associated with withdrawal," lead author Dr. Larry F. Chu, an assistant professor of anesthesia, said in a Stanford news release.

Those symptoms include agitation, insomnia, diarrhea, nausea and vomiting. Current methods of treating withdrawal symptoms aren't completely effective or cause severe side effects, requiring constant patient supervision.

"What we need is a magic bullet, something that treats the symptoms of withdrawal, does not lead to addiction and can be taken at home," Chu added.

The Stanford team plans to continue testing the effectiveness of ondansetron in treating opioid addiction and to conduct a clinical study to determine the effectiveness of an ondansetron-like drug in treating opioid addiction.

However, the researchers noted that ondansetron alone can't solve the problems caused by opioid addiction, which is a long-term, complex process that involves both physical and psychological factors.

"This is not a cure for addiction. It's naive to think that any one receptor is a panacea for treatment. Treating the withdrawal component is only one way of alleviating the suffering. With luck and determination, we can identify additional targets and put together a comprehensive treatment program," principal investigator Dr. J. David Clark, a professor of anesthesia, said in the news release.

More information

The National Institutes of Health has more about opiate withdrawal.