Washington (H24N). Naltrexone, one of only two medications approved by the Food and Drug Administration (FDA) to treat alcoholism, may
have an offspring that works better and is easier to take than its parent drug.
The compound 6-beta naltrexol is produced when Naltrexone is processed by the liver. Since everyone’s liver works differently and alcoholism damages the liver, the amount of Naltrexone an alcoholic can metabolize varies highly. If aan alcoholic’s liver is in bad shape it won’t break down the drug so it can be used, and the patient will not receive enough medication to help stop drinking.
Since people who have damaged livers need to stop drinking the most, researchers at the University of Pennsylvania’s VA Treatment
Research Center decided to test 6-beta naltrexol (which is already broken down and could bypass the liver) to see if, by itself, it had any effect on how much an individual drank. They found that it did.
Rats drank less alcohol as the amount of 6-beta naltrexol they were given increased. According to the study, which was published in the October issue of Alcoholism: Clinical & Experimental Research, the dose range tested was comparable to a standard 50mg oral dose of Naltrexone for humans.
Margaret Rukstalis, MD, the lead author of the study, is excited about 6-beta naltrexol’s potential as an anti-alcoholic agent. "Six-beta naltrexol maybe easier to give and more effective than currently available medications that help prevent alcohol relapses," said Rukstalis.
"One of the benefits of 6-beta naltrexol is that it iis longer acting. It is possible that it can be given less frequently [than Naltrexone], or, if someone misses a dose, it can still provide some protection against ‘slip’ drinking," Rukstalis said. "One nice thing
about Naltrexone, even now, is that it needs to be taken only once a day, which is very important for medication compliance, especially in an alcoholic population who may be ambivalent about taking medications to begin with. If 6 beta-naltrexol shows promise, it could potentially be given every other day, or maybe produced in a skin-patch or a long-term injectable format."
Six-beta naltrexol blocks opioid receptors in the brain, keeping alcohol from affecting brain cells and producing an alcoholic "high." The other anti-alcohol drug, Antabuse, causes severe nausea if someone who is taking it on a regular basis drinks alcohol. It is considered an aversive therapy. Naltrexone works by diminishing the
desire to drink.
According to Raymond Anton, MD, professor of psychiatry and scientific director of the Alcohol Research Center at the Medical University of South Carolina, most people’s brain cells return to
normal after alcohol leaves the system, but the brain cells of people at risk for developing alcoholism are more permanently changed. The
more such a person drinks, the more changed and dependent on alcohol their brain cells become.
"Unfortunately, the opioid neurotransmitter system probably does not explain all of the types of alcohol dependency," Anton said. "Other people may have changes in other cells and transmitters that are not
impacted by drugs like Naltrexone and 6-beta naltrexol. Future research will begin subtyping alcoholics, perhaps by using a genetic approach, so that more specific medications can be used [for a given individual]."