Australian researchers say they have found a genetic marker that could help treatment programs for opiate addiction determine how much methadone to give to maintenance patients.

Newswise reported Jan. 22 that researchers at the University of Adelaide said that certain genetic variations determine whether people are more or less efficient in distributing drugs throughout their bodies. The findings could help addiction-treatment specialists tailor methadone doses to the individual needs of users -- key because 62 percent of the methadone patients who stop treatment do so because of severe withdrawal symptoms.

"Individualized dosing may decrease the incidence of withdrawal symptoms in some people and therefore encourage them to continue with the methadone treatment," noted lead researcher Janet Coller.

The research was published in the December 2006 issue of the journal Clinical Pharmacology and Therapeutics.