Heroin abusers vary widely in therapy response

News One

NEW YORK (Reuters Health) - One dosage size is far from fitting all when it comes to a widely used treatment for heroin addiction, a study shows.

The study, of 222 U.S. veterans treated for opiate dependence, found that patients varied widely in the amount of methadone they needed to achieve abstinence. Methadone is an oral narcotic that suppresses withdrawal and reduces addicts‘ craving for heroin, and "methadone maintenance" is considered the gold standard of heroin addiction treatment.

Current guidelines recommend a minimum methadone dose of 60 milligrams (mg) per day, but many doctors in the field have argued that much lower doses can work for some patients.

The new study, published in the journal PLoS Medicine, found that some patients did in fact respond to far smaller methadone doses -- as low as 1.5 mg a day. Others, in contrast, needed nearly 200 mg to get them off of heroin.

Some of the factors that influenced patients‘ dosage needs were their overall mental health and their number of past attempts at heroin detox. Those diagnosed with post-traumatic stress disorder or depression, for example, tended to need higher methadone doses to stay clean for one month.

And counter to what might be expected, patients who‘d used lesser amounts of heroin or heroin that was less "pure" were not uniformly able to use lower doses of methadone.

The findings suggest that treatment guidelines should give advice on how to figure out an appropriate dose for any individual patient, rather than give a minimum dose for all, according to the study authors.

"Dosing guidelines should focus more heavily on appropriate processes of dosage determination rather than solely specifying recommended dosages," write the researchers, led by Jodie A. Trafton of the VA Palo Alto Health Care System in California.

Overall, about 75 percent of heroin addicts in the study were able to achieve abstinence for at least one month.

Of these patients, the researchers found, 38 percent responded to methadone doses lower than the recommended 60 mg per day. In contrast, 15 percent needed doses higher than 100 mg.

"These data," Trafton and her colleagues write, "suggest that clinicians should be allowed significant flexibility in methadone dosing as long as outcomes are positive."