Contact: Beverly Jackson
Despite decades of use in the treatment of opiate addicts, the "optimal" dose for methadone has never been agreed upon. Prescribed doses may be as low as 20-30 mg/d, and current U.S. laws discourage use above 100 mg/d. "This study," says Dr. Alan I. Leshner, Director of NIDA, "indicates that doses greater than 40-50 mg/d significantly improve treatment outcomes for clients in methadone maintenance therapy. But the finding that clients on lower doses have better treatment outcomes than those not on methadone also indicates that a comprehensive treatment program, including behavioral as well as pharmacological therapies, is the most effective treatment regimen for opiate addiction."
Dr. Eric C. Strain, lead author and a member of the Johns Hopkins University School of Medicine study team, agrees that "We found that methadone treatment, even over a very broad range of doses, significantly improves clinical outcomes for opiate addicts. But some addicts may need doses in excess of 100 mg/d."
In an earlier clinical trial, the Hopkins researchers found that low (20-25 mg) daily doses of methadone were less effective than moderate (50-80 mg) doses in reducing opioid use and in retaining patients in treatment, but that, even at the lower doses, addicts receiving methadone showed decreased heroin use. This new study was designed to ascertain whether large doses (greater than 80 mg) were more effective than moderate doses in reducing illicit drug use.
The study team recruited 192 addicts seeking treatment for opioid dependence. The study subjects had to be over the age of 18, be currently dependent on intravenous opioids, have a history of prior methadone treatment, and have a positive urine sample for opioids. The patients were admitted to a 40-week methadone treatment program and randomly assigned to 1 of 2 methadone dose schedules. Ninety-seven patients received 40-50 mg of methadone each day, and 95 received 80 to 100 mg per day. All patients received concurrent substance abuse counseling.
Prior to their admission to the study, the patients reported that they had used opioids an average of 24 times a week. During the latter part of the study, the high-dose group reported using illicit opioids once or fewer times a week, while the moderate-dose group reported using such drugs 2 to 3 times a week.
Through week 30, patients in the high-dose group had lower rates (53 percent) of opioid-positive urine samples, compared to patients in the moderate-dose group (61.9 percent). The average number of days each remained in treatment was virtually identical for the two groups: 159 days out of a possible 210 days for the high-dose group, and 157 days for the moderate-dose group. One third of the patients in the high dose group, and 11 percent of the patients in the moderate-dose group, completed the detoxification program in weeks 31 to 40.
These findings, coupled with the results of the earlier clinical trial, indicate that addicts benefit from methadone during treatment, and that improvements in keeping them in treatment occur as the methadone dose is increased at least to a moderate range (50 mg/d).
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